Boats are battered by rough waves at a marina in Miami Beach, Florida, as Hurricane Irma arrives in south Florida on Sunday. [Photo/Agencies]

As Irma left Cuba late on Saturday and directed its 215 km/h winds toward Florida, authorities on the island were assessing the damage and warning of staggering damage to keys off the northern coast studded with all-inclusive resorts and cities, as well as farmland in central Cuba.

There were no immediate reports of deaths in Cuba but authorities were trying to restore power, clear roads and warning that people should stay off the streets of Havana because flooding could continue into Monday.

Residents of "the capital should know that the flooding is going to last more than 36 hours, in other words, it is going to persist," Civil Defense Colonel Luis Angel Macareno said late on Saturday, adding that the waters reached inland about 600 meters into Havana.

As Irma rolled in, Cuban soldiers went through coastal towns to force residents to evacuate, taking people to shelters at government buildings and schools－and even caves.

Video images from northern and eastern Cuba showed uprooted utility poles and signs, many downed trees and extensive damage to roofs. Witnesses said a provincial museum near the eye of the storm was in ruins. And authorities in the city of Santa Clara said 39 buildings collapsed.

More than 5,000 tourists were evacuated from the keys off Cuba's north-central coast, where the government has built dozens of resorts in recent years.

Before slamming into Cuba, Irma had caused havoc in the Caribbean, where it ravaged such lush resort islands as St. Martin, St. Barts, St. Thomas, Barbuda and Anguilla.

On the Dutch side of St. Martin, an island divided between French and Dutch control, an estimated 70 percent of the homes were destroyed by Irma, according to the Dutch government.

Prime Minister William Marlin said about 1,600 tourists had been evacuated and efforts were being made to move 1,200 more.

Marlin said many countries and people have offered help to the Dutch side, known as St. Maarten, but authorities were waiting on the weather conditions to see how it could be coordinated. Authorities are still trying to determine the extent of damage to the island, but he said 28 police officers lost homes during the storms.

The US State Department helped more than 500 US citizens fly out of St. Martin, starting with those in need of urgent medical care, spokeswoman Heather Nauert said.

Carol Basch, 53, a tourist from Savannah, Georgia, took refuge during the storm in the bathroom of her St. Martin hotel room after windows shattered. She stayed there praying for about four hours, surrounding herself with pillows.

Some islands received a last-minute reprieve from the next storm on the horizon, Jose, as it passed by.

The US National Hurricane Center downgraded a hurricane warning for Barbuda and Anguilla. A hurricane watch also was discontinued for nearby Antigua.