Hurricane Maria has strengthened to a category five 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 260 kilometres per hour and even stronger wind gusts, the agency said on Monday.
Maria is also 70km north of the island of Martinique.
The National Hurricane Centre in Miami said on Monday evening 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.
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