Hurricane Maria has made landfall on the Caribbean island of Dominica as a dangerous Category 5 hurricane, the US National Hurricane Centre said.

Less than 90 minutes later, the centre of the storm, described by the NHC as "potentially catastrophic," passed almost directly over Dominica, on a track that would put it over Puerto Rico by Wednesday, according to the agency's latest bulletins.

There was no immediate word on the fate of Dominica, a former British colony home to 72,000 people that lies in the eastern Caribbean about halfway between the French islands of Guadeloupe, to the north, and Martinique, to the south.

But Prime Minister Roosevelt Skerrit, in a Facebook post around the time Maria made landfall, said the storm had blown the roof off his home, adding, "I am at the complete mercy of the hurricane. House is flooding." He then added, "I have been rescued."