Hurricane Earl hit the Leeward Islands in the Caribbean early Monday as it strengthened to a category two storm, packing high winds, heavy seas and the threat of storm surges.

Residents shored up homes and businesses, and stocked up on essential supplies ahead of the passage of the storm near the twin-island state.

The US-based National Hurricane Center said Earl displayed maximum sustained winds of 105 miles (165 kilometres) an hour by 0900 GMT Monday.

"Additional strengthening is forecast ... and Earl is expected to become a major hurricane by tonight or early Tuesday," it said.

Weather officials forecast more than five inches (13 centimetres) of rain from the storm, which is expected to pass northeast of Antigua.