At 11 a.m., Bertha, with sustained 70 mph winds and gusts up to 85 mph, was centered 260 miles north-northeast of Bermuda, the U.S. National Hurricane Center in Miami said. The storm was moving north-northeast at 12 mph and was expected to strengthen to regain Category 1 hurricane status with sustained winds of more than 74 mph Tuesday or Wednesday.

Tropical storm force winds were extending 140 miles from the storm center, forecasters said.

Bermuda's Royal Gazette newspaper reported 7,000 people lost electricity Monday as the storm moved east of the island.

There was no immediate report of injuries. All beaches were closed as 6-foot waves battered the coast and all flights from the island's airport, buses and ferries were canceled Monday, the newspaper said.

U.S. forecasters said the high surf battering the island would ease Tuesday although "dangerous rip currents are also occurring along the U.S. East Coast from the Carolinas through southern New England."