White House and Pentagon cleared as earthquake strikes

One of the strongest earthquakes ever recorded on America's east coast saw mass evacuations in Washington.

The Washington Monument was closed after cracks appeared and three capstones broke off the towers of the National Cathedral.

While Barack Obama was on holiday in Martha's Vineyard, staff from the White House, the Capitol and the Pentagon were evacuated. No one is thought to have died.

The US Geological Survey said yesterday's quake, which occurred just before 2pm local time, registered a magnitude of 5.8 and was centred about 40 miles north-west of Richmond, Virginia.

Two nuclear reactors at the North Anna Power Station, in the same county as the epicentre, were automatically taken off line.

Coming less than three weeks before the 10th anniversary of the September 11 attacks, the earthquake immediately triggered fears of something more sinister.

The Park Service has closed all monuments and memorials on the National Mall, and ceiling tiles fell at Reagan National Airport outside Washington.

Park service spokesman Bill Line said the Washington Monument will be closed indefinitely to keep the public safe.

In New York City, the 26-storey federal courthouse in lower Manhattan - just blocks from the site of the 2001 terror attacks on the World Trade Center - began swaying, and hundreds of people streamed out of the building.

The last quake of equal force to strike the east coast was in New York in 1944. The largest east coast quake on record was a 7.3 that hit South Carolina in 1886.

Tourists on a small North Carolina island were today ordered to evacuate as Hurricane Irene thundered towards the US. But authorities fear that not everyone will be able to leave the tiny Ocracoke Island, accessible only by boat, before the storm strikes. The hurricane has already caused chaos and destruction in Puerto Rico where more than a million people were left without power and one woman died.