United States National Hurricane Center officials have warned Tropical Storm Irene could grow into a hurricane as it batters Puerto Rico.
The United States Caribbean territory has been batted with torrential rains and winds overnight, with trees downed and widespread power outages reported.
The Dominican Republic is also under a hurricane warning with the high winds, severe rain and high tides expected Monday.
Tropical storm conditions are expected in much of the rest of the region.
Storm Irene is strengthening as it approaches the rest of the region, with winds of 110 kilometres per hour expected, nearing hurricane strength.
Tropical storm warnings have been issued for Vieques, Culebra, Saba, St. Eustatius, St. Maartin, Dominica, Barbuda, St. Kitts, Nevis, Antigua, Anguilla and Montserrat.