Train derails in Philadelphia, claims at least five lives

A passenger train has derailed in Philadelphia, killing at least five people and injuring dozens of others, officials in the US city say.

Up to 10 carriages of the Washington-New York Amtrak service went off the track on Tuesday evening. The train derailed in a suburb of Philadelphia, shortly after leaving the city's main station.

Emergency officials and fire-fighters are at the scene looking for passengers who may be trapped in the wreckage.

More than 240 people were on board Train 188, the officials say. It is not known what caused the derailment. Philadelphia Mayor Michael Nutter said at least five people died.

The National Transportation Safety Board said it was dispatching a team of investigators to the crash site.