SAN JUAN, Puerto Rico -- Hurricane Earl lashed northern Leeward Islands with heavy rain and strong winds Monday after strengthening into a Category 2 storm. Hotels were shut tightly overnight as tourists sought shelter inside their rooms.
The U.S. National Hurricane Center in Miami said Earl could become a major hurricane Monday night or early Tuesday.
"It is possible that Earl could become a Category 4 hurricane as we get into the middle to late portions of the week," hurricane center specialist Michael Brennan said.
Hurricane warnings were in effect for Antigua, Barbuda, Montserrat, St. Kitts, Nevis, Anguilla, St. Martin, St. Barthelemy, St. Maarten, Saba, St. Eustatius, the British Virgin Islands and the U.S. Virgin Islands.
Steady bands of rain began falling late Sunday on islands including Antigua, where the Grand Pineapple Beach Resort on the north side battened down early as a precaution.
Winds were heavy but had not caused any major damage, and the surf was higher than normal but not punishing, general manager Courtney Miller told The Associated Press by phone.
Earlier Sunday, islanders stocked up on food, water and supplies, set up shelters and tied down boats in harbors across the northern Caribbean as Earl blew toward the region.
Antigua's V.C. Bird International Airport closed, and regional airlines LIAT and Winair suspended flights. Cruise ships diverted to other ports in the Caribbean and Mexico to avoid the storm's path.
In St. Kitts and Nevis, authorities urged people to take all necessary precautions for the hurricane, which is dwarfing the tiny island nations and territories of the northern Caribbean.
"We really don't want any loss of life, whether by persons who are careless or by security or emergency persons trying to rescue people," said Carl Herbert, head of the local emergency management agency.
Hardware stores did a brisk business in plywood and boards as jittery residents and employees of gleaming tourist hotels prepared to safeguard windows and doors.
"We haven't been hit for quite a few years, but you may never know -- this might be the time," said Ashley Benta, from the Antiguan town of Gray's Farm.
Early Monday, Earl was about 50 miles (75 kilometers) east-northeast of St. Martin and headed west-northwest at 15 mph (24 kph), according to the center in Miami. Hurricane-force winds extended outward up to 50 miles (85 kilometers) from its center.
Earl became a hurricane Sunday morning and has continued to grow rapidly in strength, fueled by warm ocean temperatures of 86 F (30 C).
Earl could bring battering waves and storm surges of up to four feet (1.2 meters) above normal on some islands, as well as downpours that threaten to unleash flash floods and mudslides.
Forecasters say there is a chance the hurricane could brush the U.S. Mid-Atlantic region toward the end of the week, with its closest approach to North Carolina on Thursday.
In any case, the U.S. East Coast is likely to see pounding surf.
"Folks from the Carolinas northward through the Mid-Atlantic and New England need to be paying attention to Earl and the forecasts as they get updated through the week," Brennan said.
Meanwhile, the Category 1 Hurricane Danielle was bringing dangerous rip currents to the U.S. East Coast. It was weakening as it headed over the open Atlantic northeast of the British territory of Bermuda.