Residents flee Keys as hurricane approaches

Weather experts warned that Isaac was close to the Florida Keys and could be hurricane force when it swept across.

Hundreds of flights have been cancelled and oil and gas production are affected by a storm that has already killed at least six people in Haiti.

The Republican Party has been forced to delay, by a day, the start of the national convention in Tampa.

Other US states are also on alert as forecasters warn that Isaac could strengthen further.

Homes have been boarded up as people in Florida prepare for Tropical Storm Issac

Fed by the warm waters of the Gulf of Mexico, Isaac is expected to strengthen to a Category 2 hurricane with winds of 105mph before it makes landfall.

The timing and place of landfall is uncertain, but it could be midweek around the Florida-Louisiana border.

There is also a chance it may hit New Orleans on the seventh anniversary of the devastating Hurricane Katrina.

Isaac is also a large storm – it could bring significant damage to areas within 200 miles of its centre.

Last night the Florida Keys were already experiencing rain and strong winds.

Residents have boarded up windows and put down sandbags.

In Key West, Emalyn Mercer rode her bike while decked out with a snorkel and mask, inflatable arm bands and a paddle, just for a laugh. She rode with Kelly Friend, who wore a wet suit, dive cap and lobster gloves.

“We’re just going for a drink,” Mercer said.

“With the ones that are brave enough like us,” Friend added.

A steady stream of cars has carried people north along the sole road linking the Keys to the Florida mainland.

Hundreds of flights have been cancelled in and out of Miami, Fort Lauderdale and other southern Florida airports.

Hurricane watches have been put in place along the coastlines of western Florida, Alabama, Mississippi and south-eastern Louisiana.

Florida Governor Rick Scott declared a state of emergency there to make sure emergency services would be ready when the storm hit.