A state of emergency has been declared in Louisiana and Mississippi as Tropical Storm Gordon batters the US Gulf Coast.

Gordon made landfall just west of the Alabama-Mississippi border, the National Hurricane Center (NHC) said, with sustained winds of up to 70mph (110km/h).

Thousands of people were reported to be without power.

The NHC warned there could be "life-threatening" storm surges.

Gordon strengthened as it neared the coast on Tuesday, but did not reach hurricane status.

"Rapid weakening is forecast after Gordon moves inland, and is forecast to become a tropical depression on Wednesday," the NHC said in an advisory.

At 03:00 GMT the centre of the storm was reported to be 30 miles east of Biloxi, Mississippi, moving at a speed of 14mph in a north-westerly direction.

More than 27,000 customers were hit by power cuts, the Associated Press news agency reported, mostly in coastal Alabama and south-eastern Mississippi.

Oil and gas companies in the Gulf of Mexico also evacuated more than 50 platforms as the storm swept in, temporarily halting production.

The National Weather Service in New Orleans gave tips to city residents how to prepare for the arrival of the storm.

Meanwhile, New Orleans Mayor LaToya Cantrell warned: "The city's absolute number one priority is to ensure the safety of our residents."

New Orleans was devastated by deadly Hurricane Katrina in 2005.