Hurricane Dean intensified to a violent Category 5 storm Monday night, as high winds forced thousands of tourists to evacuate the coasts of Mexico and Belize.

"We're looking at a very, very, serious and life-threatening situation here," Hugh Cobb, a spokesperson for the U.S. National Hurricane Center, told Â鶹´«Ã½net late Monday.

Category 5 hurricanes -- the largest and most destructive storms possible -- have winds of more than 249 km/h. Dean is roughly the size of Texas and has already caused at least 12 deaths.

Mexico's Quintana Roo state government said about 40,000 tourists in Cancun had evacuated the area by Monday, with another 20,000 remaining.

At 2 a.m. ET Tuesday, the center said Dean had sustained winds of 260 km/h with higher gusts, and little change in strength expected before landfall.

Hurricane-force winds extend out 95 kilometres on either side of Dean's eye, and tropical-storm strength winds go out 280 km. Dean was 160 km east of Chetumal, Mexico, which is about 280 km south of Cancun, at the time of the latest advisory.

The storm is moving at 32 km/h and will continue to track either west or west-northwest.

A hurricane warning is effect from Belize to Cancun. In Belize City, officials have closed all hospitals and residents have been told to evacuate because the shelters may be too weak to survive the storm.

Cancun-Cozumel to be 'spared' direct hits

Joe Bastardi of AccuWeather told Â鶹´«Ã½net that the hurricane would likely make landfall around Chetumal.

"It's good news as far as Cancun-Cozumel goes," he said, referring to two very popular resort areas. "They will both be spared direct hits."

The relatively less populated areas to the south will bear the brunt, he said.

Dean will lose strength over the Yucatan Peninsula but will regain some power before it hits near Tampico, Mexico sometime on Wednesday. Tampico is about 350 km south of Texas. But Bastardi said the hurricane won't return to Category 4 or 5 status.

The storm has already had an impact on Mexico's oil production in the Gulf of Campeche just west of the Yucatan Peninsula.

Mexico's Pemex state oil company is pulling all 18,000 workers off its oil rigs in the Gulf of Mexico as hurricane Dean bears down.

The move will cut the company's production by 2.65 million barrels per day, representing an 80 per cent drop in output.

Tourists leave Mexico, Jamaica takes stock

Officials in the Mexican resort city of Cancun had organized additional flights to let tens of thousands of tourists leave before Dean arrived. The hotel zone was largely emptied out.

Forecasts have shifted the projected path to the south, but Cancun could still see tropical storm-force winds.

The threat of the storm comes mere months after many resorts in Cancun reopened in the wake of damage from hurricane Wilma, which hit Mexico in October 2005.

"Everyone is so much better prepared than they were for Wilma," said Jennifer Stowe, a Canadian teaching in Cancun.

"It was like a freight train," she said, recalling the noise. "Continuously for almost the whole 36 hours."

Her school is being set up as an emergency shelter.

Dean's eye passed south of Jamaica on Sunday night and the island is now assessing the storm's aftermath.

Evadne Coye, Jamaica's high commissioner to Canada, told Â鶹´«Ã½net that a full damage assessment hasn't been done yet, although three deaths are confirmed.

"We have heard from telephone calls ... that damage to the agricultural sector has been very great," she said.

Jamaica's south coast took a pounding. Coye described that area as the country's breadbasket.

"Food prices are going to be shooting up in the very near future as part of the impact of hurricane Dean," she said.

The country's vital tourism industry is centred mainly on the island's north side.

Dean bore down on the Cayman Islands late Sunday after battering Jamaica, but the wealthy British protectorate said Monday it had been spared the brunt of the storm.

Dean's eye passed some 160 kilometres south of the Caymans, and the islands were spared hurricane-force winds.

Canada has offered up to $2 million in aid for Caribbean countries damaged by the hurricane. Foreign Affairs Minister Maxime Bernier said his department has had no reports of Canadian casualties.

Dean is the first storm of the Atlantic hurricane season.

With a report from CTV's Tom Walters and files from The Associated Press