Hurricane Maria has strengthened to a Category 5 storm and is now 25 kilometres east-south-east of the Caribbean island of Dominica, the US National Hurricane Centre says.
The storm “has intensified into an extremely dangerous” hurricane, with winds of 260kp/h and even stronger wind gusts, the agency said on Tuesday.
Maria is also 70km north of the island of Martinique.
The National Hurricane Centre in Miami said on Tuesday morning (AEST) that Air Force Reserve hurricane hunter planes found that Maria had strengthened into a storm with 260km/h winds.
The hurricane is moving west-northwest at 15km/h.
“Some additional strengthening is possible tonight, but some fluctuations in intensity are likely during the next day or two,” the Miami-based weather forecaster said on Monday.
Residents of some islands fled ahead of the storm.
Beth Tamplin Jones, 45, rode out Hurricane Irma earlier this month in the pantry of a friend’s house on St. John in the US Virgin Islands.
“It was so intense,” said Ms Jones, who evacuated from St. John to Puerto Rico last week and then got a flight to Atlanta, where she planned to remain until Maria passed.
“I don’t think anybody’s ever been hit by a storm like that. To see another one coming is just so discouraging.”
US Virgin Islands Governor Kenneth Mapp warned residents not to underestimate the threat from Maria, or its potential to change track. “Just remember this is a live animal,” he said.
The island of St. Croix looked to face hurricane force winds with nearby St. Thomas and St. John seeing tropical storm force winds, Mr Mapp said, adding, “given the current conditions of St. Thomas and St. John, that’s not good.”
French weather service Meteo France issued a red alert for Martinique. Businesses were ordered to shut down, public transport services were suspended and residents were told to take shelter in their houses.
Puerto Rico, a US territory which Irma grazed as it headed toward Cuba and Florida, opened shelters and began to dismantle construction cranes that could be vulnerable to Maria’s high winds.