"Our paramount concern right now is for the safety of these students," Villaraigosa said during a late afternoon news conference. "I'm asking parents to make sure that their kids are at school tomorrow, ready to learn and ready to discuss the important issues that they were here to demonstrate about."

Middle and high school classes throughout the Los Angeles Unified School District are scheduled tomorrow to discuss a bill introduced by Rep. F. James Sensenbrenner, R-Wis., which would crack down on employers hiring illegal workers and people smuggling illegal immigrants into the country.

"We will have in-class teachings for students so that they can have conversations to deal with this issue in a very productive way," said Rowena Lagrosa, executive officer of educational services for the district. "We are being proactive so that those students will show up for school tomorrow."

Letters and recorded phone messages in English and Spanish were sent to parents throughout the district, urging them to make sure their students attend classes Tuesday, Lagrosa said.

Students participating in a mass demonstration last Friday and Monday could face discipline ranging from suspension to exclusion from certain school-sponsored functions, Lagrosa said.

It was unclear how much money the school district lost due to decreased attendance today and Friday, she said. The district receives state funding based on average daily attendance.

Darlene Robles, superintendent of the Los Angeles County Office of Education, said the more than 36,000 students who walked out of class Monday were from 26 school districts throughout the county.

The LAPD was placed on citywide tactical alert as a precaution because of the protests in various parts of the city, leading to five arrests during a demonstration at Van Nuys City Hall, Vernon said. The status allows police commanders to deploy officers beyond the end of their shifts as needed.

Four youths were arrested on suspicion of assault, while another was arrested for alleged disorderly conduct. In one instance, a student waved a large tree limb at police officers during the Van Nuys gathering, Vernon said.

Shortly after 1 p.m., about 100 student protesters took their march onto the Harbor (110) Freeway in downtown Los Angeles. The students brought traffic to a stand-still on the northbound lanes of the freeway, then broke into two groups heading both north and south on the Hollywood (101) Freeway, according to Bratton.

"Those who got on the freeway were very foolish," Bratton said. "Those cars are going 70 miles per hour with kids walking by. That's not a good mix. But, by and large, these were peaceful demonstrations."

Bratton said he did not anticipate any student protests tomorrow because the weather forecast calls for rain.

During the protest at City Hall, Alejandro Aguirre, 15, and his father Sergio said they wanted to voice their opposition to the Sensenbrenner bill.

"Right now, the most important thing to me is this," said Alejandro, a sophomore at John Marshall High School. "If I miss class, it's not as bad as if this bill passes. I can always make up homework, but this is the most important thing affecting us right now."

The Aguirres, who marched with about 500,000 people through downtown Los Angeles on Saturday, said they believe the proposed legislation unfairly targets Latino immigrants.

"This is a country of immigrants, and this country would not be possible without us," said the elder Aguirre, who emigrated from Mexico about 20 years ago and now works as a Los Angeles city planner. "We are the backbone, we work hard to get here and we work hard after we're here, but this bill is trying to take all that away."

The Sensenbrenner bill, HR 4437, would require employers to verify Social Security numbers with the Department of Homeland Security, increase penalities for immigrant smuggling and stiffen penalities for undocumented immigrants who reenter the United States after having been removed.

Under the bill, approved last December by the House of Representatives, local law enforcement agencies would be reimbursed for detaining illegal immigrants. Refugees with aggravated felony convictions would also be barred from receiving green cards.

The U.S. Senate's Judiciary Committee softened part of the immigration reform bill today by adopting an amendment by Sen Richard Durbin, D-Ill., that would protect charitable organizations and churches from criminal charges for providing aid to illegal immigrants.

The full Senate has yet to vote on the revised legislation.

"We may be illegal immigrants, but we are human," Metropolitan High School senior Melania Preciado said as she waved a Mexican flag. "We deserve the same rights as everyone else, not be treated like criminals."

"We're coming from very different, rival high schools to come together and protest against this bill because it criminalizes people from other countries, who cross the border to get jobs, to contribute to the U.S. economy," said Gustavo Dominguez, a senior at Belmont High School. "We're just here to achieve a better life, that's it."

The students outside City Hall cheered loudly when Villaraigosa came out after speaking with six students selected by protest organizers. He said their opposition to the Sensenbrenner bill was heard, but urged the students to return to class.

"You've come today, you registered your commitment to your families, your opposition to the Sensenbrenner legislation, but it's time to go back to school," Villaraigosa said. "But in your schools, I want you to work to educate the other students about why it's so important for us right now."

Villaraigosa made a second appearance around 4 p.m. asking students to go home, but was met with taunts and obscenities in Spanish.

"I knew there was a possibility that the kids would react the way that they did," Villaraigosa said. "I knew that they were still very agitated, but I made it absolutely clear that even though they have a right to demonstrate, they also have a duty to return to school."

Extra riot police are being deployed in Paris ahead of an afternoon march.

The state-run SNCF rail company said only two out of three of its high-speed trains, about 40% of other long-distance trains and about half of its suburban lines were operating.

In Paris, the underground rail network and the RER suburban service were also badly hit.

Disruption was also reported in Bordeaux, Lille, Marseille, Nancy, Strasbourg and Valenciennes.

Airport authorities warned of delays and cancellations and urged passengers to check with their airlines.

Schools, post-offices, banks, government offices and unemployment bureaux were also expecting serious disruption, on a fifth day of nationwide demonstrations against Prime Minister Domininque de Villepin's First Employment Contract (CPE).

'Test of resolve'

Protesters are bitterly opposed to the CPE, which allows employers to end job contracts for under-26s at any time during a two-year trial period without having to offer an explanation or give prior warning.

The government says it will encourage employers to hire young people but students fear it will erode job stability in a country where more than 20% of 18 to 25-year-olds are unemployed - more than twice the national average.

The BBC's Caroline Wyatt in Paris says these latest demonstrations are a real test of the prime minister's resolve, and it is hard to see how he can break the stalemate.

To find a solution without losing face - or ground to his main rival for the presidency, Interior Minister Nicolas Sarkozy - is proving the biggest challenge of Mr de Villepin's political career, our correspondent adds.

The main unions refuse to negotiate until he withdraws the contracts - while Mr de Villepin insists he will not be dictated to by the streets.

In France, street protests have long proved a powerful political weapon. Yet there are serious fears on all sides about a breakdown in public order if these protests continue.

Riot police will be stationed in Paris to try to stop a repeat of last Thursday's scenes, when more than 400 people were arrested and dozens injured as protests turned violent.

The protests by university and high school students over the new law have drawn tens of thousands of demonstrators on recent nights. French police are promising increased surveillance on the country's rail network before nationwide strikes and protests planned for Tuesday.

"Recent demonstrations have occurred at times in areas frequented by tourists," the U.S. announcement said. "Some of the demonstrations may be announced, while others may be spontaneous. Police have responded by using tear gas. U.S. Embassy personnel have been advised to avoid all demonstrations and large gatherings."

The announcement expires April 30.

The jobs law, meant to put the brakes on sky-high unemployment among young people and make France's economy more flexible, would allow employers to more easily hire - and fire - workers under age 26. Critics feel it will eat into job protections and leave young workers even more vulnerable.

Last week, a department warning about travel to Italy became a campaign issue in that country's upcoming national elections.

The department told Americans that Italy continues to be under heightened public threat by al-Qaida and other Islamic extremists for its continued participation in multinational activities in Iraq and Afghanistan.

Italian Prime Minister Silvio Berlusconi, a Washington ally, defended the U.S. government's right to inform its citizens. His center-left opponent Romano Prodi said the advisory created a climate of fear.

There were reports of fighting as crowds took to the streets of the French capital amid a hail storm.

Extra riot police had been deployed before the march. A rally in Paris last week led to running battles.

A nationwide strike has closed large parts of France's transport networks.

Workers and students in more than 100 cities are calling for the government to scrap the controversial employment contracts.

Unions reported a huge turnout for a march in Marseille, and large crowds were expected in other cities.

Travel chaos

As transport workers joined the strike, commuters were left battling with widespread disruption as large parts of the country's rail, bus and air networks came to a halt.

The trade unions and student groups are hoping Tuesday's protest in Paris will be the largest so far, the BBC's James Menendez says.

French Interior Minister Nicolas Sarkozy met police in the capital before the march, and told them to only get tough with those he called delinquents.

"My first instruction is that you protect the demonstrators, especially the youngest ones," he said.

"The second instruction is to arrest as many thugs, that means delinquents, as you can."

Unions said between 200,000 and 250,000 people turned out for a march in Marseille - many more than at the previous worker-student demonstrations on 18 March.

In the western city of Nantes, police put the figure at 42,000, more than double the 18 March turnout. Le Mans, Rouen and Tours also reported increased crowds.

As transport workers joined the strike, the state-run SNCF rail company said only two out of three of its high-speed trains, about 40% of other long-distance trains and about half of its suburban lines were operating.

In Paris, the underground rail network and the RER suburban service have already been badly hit by the strike.

Disruption was also reported in Bordeaux, Lille, Marseille, Nancy, Strasbourg and Valenciennes.

Airport authorities warned of delays and cancellations and urged passengers to check with their airlines.

Schools, post-offices, banks, government offices and unemployment bureaux are also experiencing serious disruption.

'Test of resolve'

Protesters are bitterly opposed to the First Employment Contract (CPE), which allows employers to end job contracts for under-26s at any time during a two-year trial period without having to offer an explanation or give prior warning.

The BBC's Caroline Wyatt in Paris says these latest demonstrations are a real test of the Prime Minister Dominique de Villepin's resolve, and it is hard to see how he can break the stalemate.

To find a solution without losing face - or ground to his main rival for the presidency, Interior Minister Nicolas Sarkozy - is proving the biggest challenge of Mr de Villepin's political career, our correspondent adds.

FRENCH STUDENT PROTESTS
2005: Conservative education minister withdraws key elements of school reform after pupils and teachers protest

1995: Protests over pension reforms push Conservative PM Alain Juppe from office two years later

1994: Conservative PM Edouard Balladur abandons law cutting wages for young people in job training in face of month of protests

1986: Mass protest leads Conservative government to shelves university reform plan

May 1968: Uprisings help undermine legitimacy of President Charles de Gaulle, who stands down following year
The government says it will encourage employers to hire young people but students fear it will erode job stability in a country where more than 20% of 18 to 25-year-olds are unemployed - more than twice the national average.

"We are more than three million on the street. It is historic. It is unthinkable for the prime minister to stay fixed in his position," said Bernard Thibault of the CGT union.

"For us there is just one issue and that is withdrawal of this reform," he said.

Unions said between 200,000 and 250,000 people turned out for a march in Mediterranean port of Marseille, many more than on a last day of worker-student demonstrations on March 18.

In the western city of Nantes police put the figure at 42,000, more than double the turnout of March 18.

Le Mans, Rouen and Tours also reported increased crowds.

The biggest demonstration was due in the afternoon in Paris, with police on high alert for outbreaks of violence.

An alliance of unions, students and left-wing political parties is seeking the withdrawal of Prime Minister Dominique de Villepin's First Employment Contract (CPE), which makes it easier to hire and fire under 26 year-olds.

Speaking in the northern town of Douai Monday evening, Sarkozy - who is interior minister as well as UMP president - implicitly criticised Villepin for failing to consult with unions and employers before drawing up the First Employment Contract (CPE), which has sparked three weeks of street protests.

"For change to succeed, there has to be social dialogue. Social dialogue is an essential precondition for the success of any reform," Sarkozy said.

"We must rediscover the spirit of compromise, in which each side takes a step towards the other in order to build a more just society.... No government texts on social issues that have not been the subject of prior consultation, and no blockages and ultimatums by unions," he said.

Speaking before UMP deputies Tuesday Sarkozy recommended a period of "non-application (of the CPE) pending negotiations between the social partners to search for a compromise."

Villepin - widely regarded as Sarkozy's rival ahead of next year's presidential election - has refused to withdraw the CPE, instead offering "adjustments" outside the framework of the law.

Commentators said Sarkozy was treading a careful path, officially expressing solidarity with the prime minister but trying to limit the damage from the campaign of worker-student protests to his own political ambitions.

"As a presidential candidate (Sarkozy) does not want to be carried down with the rest of the right in the storm over the CPE.... But he cannot take his criticism beyond these repeated appeals for compromise or he could face accusations of betrayal of his own party," said Le Figaro newspaper.

Villepin has been comforted by opinion polls that show that even if two-thirds of the French oppose the CPE, some 74 percent of UMP voters believe he should stick to his guns.

For the two leaders it was an ironic reversal of roles, as Villepin was until recently cast as the socially conscious gradualist reformer, and Sarkozy as a supporter of a clean break - 'la rupture' - with France's economic model.