Bermudan officials were carefully watching Hurricane Fabian (search) as the storm swirled across the Atlantic Ocean on a northwest path Wednesday that could threaten the island.

The storm was about 700 miles south of Bermuda (search) at 11 a.m. EDT and was moving northwest at about 10 mph.

The Bermudan Weather Service was expected to issue a hurricane watch Thursday.

Jack Beven, a specialist at the U.S. National Hurricane Center (search) in Miami, said the Category 4 hurricane was expected to pass west of Bermuda by Friday or Saturday, and could possibly strike the island nation directly.

He said there is little chance of the hurricane hitting the United States.

Fabian had maximum sustained winds of 135 mph at midday Wednesday, up slightly from 130 mph overnight. Forecasters said fluctuations in the storm's strength were expected because of its size.