HURRICANE EARL PROMPTS US EAST COAST EVACUATIONS

Evacuations have begun in areas of the United States East Coast likely to be hit by Hurricane Earl.

The hurricane has strengthened to a category four storm again, generating sustained winds of 233km/h British Broadcasting Corporation reports.

President Barack Obama said officials needed to be ready for a 'worst case' scenario in a call to the US Federal Emergency Management Agency.

The governors of North Carolina, Virginia and Maryland declared a state of emergency in response to the situation.

US officials have ordered a mandatory evacuation for thousands of visitors and residents on Ocracoke Island and Hatteras Island in North Carolina.

Both islands are part of North Carolina's Outer Banks, a region popular with tourists.

Fema has warned people along much of the Eastern Seaboard of the US to be vigilant and follow official bulletins.

Forecasters at the National Hurricane Centre said they expected the hurricane to turn north and then run parallel to the East Coast.

They temporarily downgraded Earl to a category three storm on Wednesday, but the hurricane strengthened to a category four again later in the day.

'The most important thing for people living in Earl's potential tract to do is to listen to and follow the instructions of their local officials,' Fema administrator Craig Fugate said.