Miami  - At least six people have died in the US state of Florida, which has been drenched by monsoon-like rains because of Tropical Storm Fay, officials said Friday.

The deaths were caused by drownings and car accidents, Florida Governor Charlie Crist said.

The National Guard was involved in rescue operations in the northern coastal city of Melbourne. Residents claimed to have seen alligators swimming in the muddy waters that swirled around their homes.

Fay was weakening and slowly edging westward across Florida's northern peninsula at 7 kilometres per hour, the National Hurricane Centre in Miami said. It warned of storm surge flooding of 2 to 4 feet above normal tides along the Florida Gulf Coast.

The storm came ashore in Florida for the third time on Thursday, dumping 76 centimetres of rain in some parts, flooding roads, damaging homes and crops, and leading President George W Bush to declare an emergency - a move that would provide federal funds for relief efforts.

Fay first hit Florida on Monday at its southern tip, Key West, and then crossed the south-western portion of the peninsula before again moving offshore.

It earlier left as many as 50 people dead in flooding and landslides in Haiti and the Dominican Republic. (dpa)