Hurricane Irene is pummelling the US east coast after making landfall in North Carolina.

飓风艾琳在加利福尼亚北部登陆之后，袭击了美国东海岸地区。

At least eight people have been killed in North Carolina, Virginia and Florida, as Irene sweeps north.

The 500-mile wide storm, with winds of around 80mph (129km/h), is moving slowly northwards. New York and other large cities are in its predicted path.

More than two million people have been ordered to leave their homes after warnings of storm surges and flooding.

New Jersey¹ Governor Chris Christie announced on Saturday afternoon that "over a million people have left the Jersey shore in the last 24 hours".

In New York City, 300,000 people living in low-lying areas have been told to leave in an unprecedented² mandatory³（强制的） evacuation.

Mayor Michael Bloomberg said those who had not evacuated⁴ should now stay put until the storm had past.

"The edge of the hurricane is finally upon us," he told reporters.

"The time for evacuations is over. At this point, if you haven't evacuated, our suggestion is you stay where you are."

More than 90 shelters with room for about 70,000 people have been opened in New York but by early evening on Saturday only about 5,500 people had checked in.

New York's entire transit⁵ system of subways, buses and commuter⁶ rails stopped running at midday on Saturday - the first time officials have closed the network because of bad weather.

It was not expected to reopen until at least Monday. Airports are also closing.

Energy firm Con⁷ Edison also shut down miles of steam pipes under the city to prevent explosions if they come into contact with cold water.

President Barack Obama, who cut short his holiday to return to Washington, had a conference call about the hurricane with emergency officials on Saturday.

He earlier warned Irene could be "a historic hurricane" and that everyone should take the storm seriously.

The National Hurricane Center has downgraded Irene from a category two to a category one hurricane but says winds gusting⁸ up to 90mph extend outwards⁹ some 90 miles from the eye of the storm. Tropical-force winds extend as far as 290m.

The NHC expects Irene to weaken after hitting North Carolina, but it is forecast to remain a hurricane as it moves north along the Atlantic coast on Sunday.

Irene remains¹⁰ a "large and dangerous" storm, US Homeland Security Secretary Janet Napolitano warned on Saturday.