FELIPE CARRILLO PUERTO, Mexico — Hurricane Dean slammed into the Caribbean coast of Mexico today as a roaring Category 5 hurricane, the most intense Atlantic storm to make landfall in two decades. It lashed remote Mayan villages as it raced across the Yucatan Peninsula to the heart of Mexico’s oil industry.

Dean’s path was a stroke of luck for Mexico: After killing 13 people in the Caribbean, it made landfall along a sparsely populated coastline, well to the south of the major resorts where 50,000 tourists had been evacuated.

It weakened to a Category 1 storm, with maximum sustained winds of 85 mph, but was expected to grow back into a powerful hurricane as it draws fuel from the warm waters of the lower Gulf of Mexico, where more than 100 offshore oil platforms were evacuated ahead of the storm.

“We often see that when a storm weakens, people let down their guard completely. You shouldn’t do that,” a hurricane specialist, Jamie Rhome, said. “This storm probably won’t become a Category 5 again, but it will still be powerful.”

When Dean first struck land near the cruise port of Majahual, it had sustained winds near 165 mph and gusts that reached 200 mph — faster than the takeoff speed of many passenger jets. It had an expected storm surge of 12 to 18 feet above normal tides and dumped huge amounts of rain on low-lying areas where thousands of Mayan Indians live in stick huts in isolated communities.

With the storm still screaming, there were no immediate reports of deaths, injuries or major damage, Quintana Roo Governor Felix Gonzalez told Mexico’s Televisa network, though officials had not been able to survey the area.

Soldiers evacuated more than 250 small communities, but some turned away soldiers with machetes and refused to leave or hid when the army evacuated the area, a spokesman for the state of Quintana Roo, Jorge Acevedo, said. Their fate was unknown.

The eye passed directly over the state capital of Chetumal, where residents were ordered to stay home until 10 a.m. today after a harrowing night with windows shattering and heavy water tanks flying off of rooftops. Sirens wailed constantly as the storm battered the city for hours, hurling billboards down streets. All electricity was down.

Just across the border in Belize, trees fell and debris flew through the air. The government evacuated Caye Caulker and Ambergris Caye — both popular with American tourists — and ordered a dusk-to-dawn curfew from Belize City north to the Mexican border.

In the largely Mayan town of Felipe Carrillo Puerto, about 30 miles north of the eye’s westward path, people stared from their porches at broken tree limbs and electrical cables crisscrossing streets flooded with ankle-deep water.

Tin roofing ripped from houses clunked hollowly as it bounced in the wind whistling through town.

“We began to feel the strong winds about 2 in the morning and you could hear that the trees were breaking and some tin roofs were coming off,” a 36-year-old store employee, Miguel Colli, said. “Everyone holed up in their houses. Thank God that the worst is over.”

In the Belizean town of Corozal, about nine miles south of Chetumal, Dean flipped over a residential trailer, detached roofs from houses, ripped plywood off windows, and spread floodwaters as high as 3 feet. No deaths or major injuries were reported there or in Belize City, where thousands evacuated to higher ground.

By 1 p.m., Dean had weakened to a Category 1 hurricane with winds of 85 mph. It was about 45 miles southeast of Campeche and was moving west at 18 mph, according to the National Hurricane Center.

Dean’s path takes it directly through the Cantarell oil field, Mexico’s most productive, with dozens of oil rigs and three major ports. All were shut down just ahead of the storm, resulting in a production loss of 2.7 million barrels of oil and 2.6 billion cubic feet of natural gas a day. The path also veers toward Mexico’s only nuclear plant, where a state official said 2,000 buses were brought in to evacuate personnel if necessary.

The Laguna Verde nuclear plant, which is more than 20 years old and has endured other severe weather with no problems, implemented emergency procedures and remains online, a spokesman for Mexico’s Federal Electricity Commission, Estefano Conde, said. “I can assure you that everything is well taken care of,” he said.

Dean was to expected slam into the central Mexican coast as a major hurricane tomorrow afternoon about 400 miles south of the Texas border. America was expected to see few effects from the storm.

President Calderon was cutting short his trip in Canada where he met with President Bush and Prime Minister Harper of Canada so that he could travel today to the hardest-hit areas. Mr. Bush offered American assistance and expressed his concern for the citizens of Mexico and elsewhere whose lives were effected.

“We stand ready to help,” Mr. Bush said with Mr. Calderon at his side. “The American people care a lot about the human condition in our neighborhood and when we see human suffering we want to do what we can.”

The American space shuttle Endeavour landed a day early today, its mission cut short by the initial possibility that Dean could pose a threat to Mission Control in Houston.

The storm picked up strength after brushing Jamaica and the Cayman Islands and became a monstrous Category 5 hurricane yesterday. Jamaica postponed August 27 general elections in order to survey damage, which was extensive in the capital and the island’s east.

Dean is the first Category 5 to make landfall in the Atlantic region since Hurricane Andrew hit south Florida in 1992.

Insured losses from the storm are likely to range between $750 million and $1.5 billion, most of it Jamaica, according to latest estimates by Risk Management Solutions, which calculates hurricane damage for the insurance industry.

Cancun’s tourist strip is still marked with cranes used to repair the damage from 2005’s Hurricane Wilma, which caused $3 billion in losses.