With the region still traumatised by 2005 hurricanes Katrina, Rita, Dennis and Wilma, the National Hurricane Center predicted Alberto could turn into a hurricane and hit Florida's Gulf coast on Tuesday.

"Preparations to protect life and property should be rushed to completion," said NHC forecaster Richard Pasch.

About 21,000 living in mobile homes or low-lying coastal areas were affected by the evacuation order, according to local media.

Authorities urged residents to take the order seriously.

Parts of western Florida were put under a hurricane warning, including the city of Tampa, where a small plane slammed into a house, killing one person. Authorities said it was unclear whether the severe weather already affecting the area played a role in the crash.

At 10 pm Monday (0200 GMT Tuesday) the center of the storm was 150 kilometers (95 miles) south-southeast of Apalachicola, Florida, and packed maximum sustained wind of 110 kilometers per hour (70 miles per hour.)

The National Hurricane Center said the storm could develop into a hurricane before its expected landfall in western Florida Tuesday.

Cuban authorities on Monday evacuated 28,000 people as the storm swept past the island packing winds of almost 70 miles (115 kilometers) an hour.

Eight people were injured, four homes were destroyed and 48 others damaged by a tornado at Nueva Paz, south of Havana, which was whipped up by Alberto, television reports said.

Air and sea transport to the Isle of Youth, south of Havana, was cut off by the storm, Cuban television reported. Nine people have been killed in bad weather in Cuba in the past two weeks.

Alberto is the first storm since last year's record-smashing season of 28 named storms, 15 of which became hurricanes.

Several of the hurricanes blasted across Florida, including the season's worst, Katrina, which left 1,300 people dead and tens of thousands homeless along the Louisiana and Mississippi Gulf Coast.

The city of New Orleans is still struggling to recover and engineers have warned its levees may not withstand another Katrina-style battering.

The hurricane season officially started on June 1 and lasts until November 30.

US weather experts are forecasting between eight to and hurricanes -- as many as six of them major -- this year.

"Six people were injured in the incident and one or two bodies might still be trapped under the debris," Gopika Das, a magistrate in North Tripura, told AFP by telephone.

"The villagers were sleeping when the incident took place," he added.

Flood control officials said some 4,000 people were displaced when floodwaters submerged the northern Tripura town of Dharmanagar.

All major rivers in Tripura, bordering Bangladesh, are flowing above the danger level, the officials said.

In Assam, three women were killed Monday night in a landslide in Chandranathpur village in the southern Cachar district, about 310 kilometers from the states main city of Guwahati.

"Three women died and eight more were seriously injured in the incident when mounds of earth from a hillock trapped sleeping villagers," a civil official in Cachar said by telephone.

The latest deaths bring to 148 the number of people killed nationwide in weather related incidents since the monsoon hit India on May 18.

An Assam Flood Control department official said nearly 71,000 people had been affected by floods that began in the state May 31 with an estimated 2,000 villages hit.

"The affected people have been shifted to safer places with relief materials distributed among the flood-hit victims," a government statement said.

The main river, the Brahmaputra, had broken its banks along Majuli, the worlds largest river island, 350 kilometers from Guwahati.

"At least 12,000 hectares (30,000 acres) of land have been submerged in Majuli due to flooding," a government official in Majuli said.

Road and rail communications have been hit in some parts of Assam with floodwaters overflowing highways and breaching rail tracks.

According to the Central Water Commission, the Brahmaputra is flowing above the danger level in at least eight places.

The 2,906-kilometer (1,816-mile) river -- one of Asia's longest -- traverses China's Tibet region, India and Bangladesh before emptying into the Bay of Bengal.

Every year the monsoon causes the river to flood, submerging paddy fields, washing away villages, drowning livestock and killing people in Assam, a remote state of 26 million people.

In 2004, at least 200 people died and more than 12 million were displaced in the floods.