BRIDGETOWN, Barbados — Tropical Storm Matthew lashed islands in the eastern Caribbean with heavy wind and rain Wednesday night as it gained strength and headed west into open waters.

Tropical storm-force winds extended out for 185 miles (295 kilometers) as Matthew crossed through the southernmost islands of the Lesser Antilles and headed into the open Caribbean Sea. There were no immediate reports of damages or injuries as businesses, airports, schools and government offices remained closed throughout the area.

Dominica Prime Minister Roosevelt Skerrit told people on that island, where tropical storms have turned deadly in the past, to stay indoors as heavy rain caused flooding in some areas.

“We want to advise people to stay home as much as possible so as not to be exposed to the possible hazards out there. Be safe everyone and let us all pray for better weather conditions,” Skerrit said.

Many trees were down across the island of Barbados and there were isolated power outages, according to its National Emergency Operations Center.

The National Emergency Management Organization of St. Vincent said about 90 people were moved into emergency shelters because their homes were in low-lying areas that were expected to flood as the area received up to 8 inches (15 centimeters) of rain.

The U.S. National Hurricane Center in Miami said Matthew had maximum sustained winds of 65 mph (100 kph) with higher gusts. A wind gust of 89 mph (143 kph) was reported in Martinique.

The storm was on track to head across the southeastern Caribbean Sea, an area that gets relatively few storms compared to the rest of the region. A tropical storm warning was in effect for the islands of Guadeloupe and Martinique, St. Lucia, Dominica, St. Vincent, and the Grenadine Islands, and a tropical storm watch was up for Aruba, Bonaire and Curacao.

Matthew was expected to become a hurricane by Thursday evening while staying out to sea, but over the weekend it likely would turn north and pose a threat to land in Jamaica, Cuba and Haiti.

Late Wednesday, Matthew was centered about 370 miles (595 kilometers) south-southeast of San Juan, Puerto Rico, and 410 miles (665 kilometers) east-northeast of Curacao and was moving west at 15 mph (24kph).