© AP Photo/Hussein Malla
Beirut - A mass protest calling for sweeping changes in Syria's authoritarian regime turned bloody Friday, with the government and protesters both claiming to have sustained heavy casualties as the country's three-week uprising entered a dangerous new phase.

Human rights activists and witnesses said Syrian security forces opened fire on tens of thousands of protesters in the volatile southern city of Daraa, killing 25 people and wounding hundreds. But state-run TV said 19 policemen and members of the security forces were killed when gunmen opened fire on them.

It was the first significant claim of casualties by the Syrian government, which has contended that armed gangs rather than true reform-seekers are behind the unrest - and it could signal plans for a stepped-up retaliation.

Protest organizers have called on Syrians to take to the streets every Friday for the past three weeks, demanding change in one of the most rigid nations in the Middle East. Protests were held in several cities across the country Friday as the movement showed no sign of letting up, despite the violent crackdowns.

Syria's National Organization for Human Rights said at least 32 people were killed nationwide on Friday. That lifts the death toll from three weeks of protests to more than 170 people.

The protests have shaken the regime of President Bashar Assad, whose family has ruled Syria for more than 40 years. Assad, a British-trained eye doctor, inherited power from his father 11 years ago and tried to help the country emerge from years of international isolation and lift Soviet-style economic restrictions.

But despite early promises of social and political reform, Assad has slipped back into the autocratic ways of his father.

Assad has offered some limited measures of reform as the protests gathered steam, such as firing local officials and forming committees to look into replacing the country's despised emergency laws, which allow the regime to arrest people without charge. On Thursday, he granted citizenship to thousands of Kurds, fulfilling a decades-old demand of the country's long-ostracized minority.

But the persistent demonstrations underline how Assad's gestures of change have failed to mollify a growing movement that is raising the ceiling on its demands for concrete reforms and free elections.

"The protests are about Syrians wanting freedom after 42 years of repression," Murhaf Jouejati, a Syria expert at George Washington University, told The Associated Press. "So Mr. Assad may fire all the people he wants, this still doesn't touch on the basic issues and the basic demands of the protesters."

The witness accounts coming out of Syria could not be independently confirmed because the regime has restricted media access to the country, refusing to grant visas to journalists and detaining or expelling reporters already in the country. Daraa has largely been sealed off and telephone calls go through only sporadically.

But witnesses, who spoke to the AP independently of each other, said Daraa residents turned mosques into makeshift hospitals Friday to help tend to hundreds of wounded protesters.

One man who helped ferry the dead and wounded to the city's hospital said he counted at least 13 corpses.

"My clothes are soaked with blood," he said by telephone from Daraa. Like most activists and witnesses who spoke to The Associated Press, he requested anonymity for fear of reprisals.

A nurse at the hospital said they had run out of beds; many people were being treated on the floor or in nearby mosques.

Videos posted on YouTube showed demonstrations in at least 15 towns, large and small, across the country. The videos could not be independently confirmed, but they appeared to show the most widespread gatherings since protests began.

Ammar Qurabi, who heads Syria's National Organization for Human Rights, said 32 people were killed nationwide: 25 in Daraa, three in the central city of Homs, three in the Damascus suburb of Harasta and one in the suburb of Douma.

Douma has become a flashpoint after eight people were shot dead there last Friday. One activists said tens of thousands protested and dispersed peacefully in the early afternoon, but he saw security forces open fire later in the evening as a group tried to enter Douma. He said he saw security forces taking the body away.

Syria had appeared immune to the unrest sweeping the Arab world until three weeks ago, when security forces arrested a group of high school students who scrawled anti-government graffiti on a wall in Daraa.

Protests then exploded in cities across the country.

A city of about 300,000 near the border with Jordan, Daraa is suffering sustained economic effects from a years long drought.

Elizabeth A. Kennedy and Diaa Hadid in Cairo contributed to this report.