Police are continuing their hunt for arsonists who set fire to a Thames Train travelling from Banbury to Paddington.

The fire, on the 10.40pm service, caused an estimated £250,000 worth of damage to a carriage.

Insp Chris Connell, of British Transport Police, said: "This was a very irresponsible action that could have killed people. Thankfully no-one was hurt.

"This incident was an extremely serious offence which carries a sentence of life imprisonment."

Last Monday's blaze happened when seat cushions were piled up in the carriage, and set alight.

Firefighters were called after smoke was seen coming from the carriage when the train reached Reading station at about 11.40pm.

Martin Walter, Thames Trains director of communications, said: "This was a reprehensible act which put lives in danger. Not only will it now inconvenience us, but it will inconvenience passengers, as it means some train services will be a carriage short, which will lead to overcrowding."

A man wearing a black coat, possibly travelling with his girlfriend, was seen piling the cushions up in the carriage before the fire.

Police are now examining CCTV footage of the incident.

Insp Connell added: "We want to speak to anyone who witnessed the incident."

Anyone with information should contact British Transport Police on 0207 3915275.