Hurricane Maria swept over the small island of Dominica with catastrophic winds overnight, starting a charge into the eastern Caribbean that threatens islands already devastated by Hurricane Irma and holding the possibility of a direct hit on Puerto Rico.

Fierce winds and driving rain lashed mountainous Dominica for hours as Maria caused flooding and tore roofs from homes as an extremely dangerous Category 5 storm. A police official on the island, Inspector Pellam Jno Baptiste, said late Monday there were no immediate reports of casualties but it was too dangerous for officers to do a full assessment as the storm raged outside.

“Where we are, we can’t move,” he said in a brief phone interview while hunkered down against the region’s second Category 5 hurricane this month.

By early Tuesday, Maria had weakened slightly to a still major Category 4 storm after pounding the small Caribbean island nation. It then regained Category 5 strength. Forecasters cautioned that fluctuations in intensity were to be expected.

Forecasters consider a Category 5 hurricane as major, extremely dangerous and capable of catastrophic winds.

On the forecast track, the eye of Maria will move over the northeastern Caribbean Sea Tuesday and approach the Virgin Islands and Puerto Rico Tuesday night and Wednesday, the U.S. National Hurricane Center said.

Dominica Prime Minister Roosevelt Skerrit earlier captured the fury of Maria as it made landfall. “The winds are merciless! We shall survive by the grace of God,” Skerrit wrote at the start of a series of increasingly harrowing posts on Facebook.

A few minutes later, he messaged he could hear the sound of galvanized steel roofs tearing off houses on the small rugged island.

He then wrote that he thought his home had been damaged. And three words: “Rough! Rough! Rough!”

A half hour later, he said: “My roof is gone. I am at the complete mercy of the hurricane. House is flooding.” Seven minutes later, he posted that he had been rescued.

Skeritt said there were initial reports of “widespread devastation” on the small island, adding that his “greatest fear” is that the people of Dominica will wake to news of “serious physical injury and possible deaths.”

The French island of Martinique escaped Hurricane Maria largely unscathed but a communications blackout with Guadeloupe meant it would be several more hours before damage there could be assessed, a senior French Civil Protection official told the Reuters news service Tuesday.

Authorities in the U.S. territory of Puerto Rico warned that people in wooden or flimsy homes should find safe shelter before the storm’s expected arrival.

“You have to evacuate. Otherwise, you’re going to die,” said Hector Pesquera, the island’s public safety commissioner. “I don’t know how to make this any clearer.”

To the north, Hurricane Jose stirred up dangerous surf and rip currents along the U.S. East Coast, though forecasters said the storm was unlikely to make landfall. Big waves caused by the storm swept five people off a coastal jetty in Rhode Island and they were hospitalized after being rescued.

A tropical storm warning was posted for coastal areas in Rhode Island and Massachusetts, and tropical storm watches were up for parts of New York’s Long Island and Connecticut. Jose’s center was about 365 miles south of Nantucket, Massachusetts, early Tuesday and moving north at 9 mph. The storm had maximum sustained winds of 75 mph.