Police swooped on Twickenham station this morning after an off-duty officer spotted a commuter carrying a knife and a fight broke out.

A police spokesman confirmed an off-duty officer saw a man in possession of a knife on a train and tried to apprehend him. A fight then broke out between the officer and a commuter, the spokesman said.

The off-duty officer called back up and two police cars and an ambulance were sent to the train station at 8.45am.

Officers handcuffed the man, believed to be in his late 20s, and searched his backpack on the street outside the station.

A spokesman said: "This was a very minor incident where a member of the public did not appreciate an off-duty officer trying to carry out his duties and resulted in a scuffle.

"The man was seen to be in possession of a knife and police will respond as neccessary."

Eyewitnesses said one man was arrested and another was being interviewed by officers at the scene.

More to follow.