The U.S. National Hurricane Center says Tropical Storm Irene is just below hurricane strength as is moves across eastern Puerto Rico with winds of 110 kilometers per hour.

While the Dominican Republic has downgraded a hurricane warning for its southern coast to a tropical storm warning, the northern coast remains under a hurricane warning. A hurricane warning is also in effect in Puerto Rico.

A hurricane watch is in effect for the U.S. Virgin Islands and the central Bahamas.

Tropical storm conditions are expected in much of the rest of the region.

Irene's substantial rainfall of up to 25 centimeters, and twice that in isolated areas, could cause life-threatening flash floods and mudslides, as well as large and dangerous waves.