LONDON (AFP) -- An underground metro train carrying 76 passengers derailed late on Friday in central London but there were no reported injuries, police and rail authorities said.

"There was a very low speed derailment" on an eastbound Piccadilly Line train, said a spokesman for London Underground, the body which runs the capital's metro network. "There were no reported injuries. As far as we understand at this time only the last wheels on the last carriage came off."

Passengers walked to safety through carriages and on to another train which was brought into position in front of the derailed service.

"We don't know the cause of the derailment. There will be a full investigation," said the spokesman for London Underground.

He added there would be disruption to services but was unable to say how long they would last.

Sergeant Bob Alleway, of British Transport Police, said one carriage had been derailed but all carriages remained upright during the incident, which happened at 09:49 P.M. (2049 GMT) near Barons Court station.

Earlier this year the Central Line on the Tube, as London's underground train network is known, was closed for three months following a derailment at Chancery Lane station in January which left 32 people injured.

A report into the incident found that the accident was caused by gearbox failure.

The investigation concluded the accident should have been prevented and made 24 recommendations so Tube bosses could "address the deficiencies identified".

But fresh safety fears were raised in August over the 10-year-old fleet of trains which operate on that line after a union claimed cracks were discovered on trains.