The Dominican Republic and Haiti are on alert as the first Atlantic hurricane of the 2011 season approaches the Caribbean nations after battering the U.S. territory of Puerto Rico.

Forecasters say the center of Hurricane Irene is expected to pass Monday near the northern coastlines of the two countries that share the island of Hispaniola, with maximum winds of 130 kilometers an hour.

The Dominican government ordered evacuations of vulnerable coastal areas and prepared more than 1 million food rations for the population.

The United Nations says its personnel in Haiti have begun operations to raise public awareness about the storm and assess evacuation needs. Hundreds of thousands of Haitians remain in makeshift shelters after a devastating earthquake last year.

The National Hurricane Center in Miami said in its latest bulletin that Irene was about 80 kilometers north-northeast of Punta Cana in the Dominican Republic, moving to the west-northwest.

Forecasters expect the storm to intensify as it moves near or over the Turks and Caicos Islands and the Bahamas in the coming days, with winds reaching a maximum speed of about 180 kilometers an hour.

They predict the storm will move northwest along the east coast of the U.S. state of Florida later in the week before possible landfall as a major hurricane in South Carolina.

Irene intensified into a hurricane over Puerto Rico before dawn Monday, flooding streets, knocking down trees and cutting power to about 1 million residents. There were no reports of serious injuries.

Puerto Rico's governor, Luis Fortuno, declared a state of emergency to mobilize aid from the U.S. federal government. Schools, government offices and businesses in the territory remained closed Monday.