A south east London station was evacuated last night after a man claiming to have a gun ran on to the tracks and started singing a UB40 song, passengers say.

Shocked bystanders watched as the man allegedly jumped on to the railway line and started "running up and down" while belting out a hit by the Birmingham reggae outfit.

Officers from British Transport Police and the Met arrived swiftly at the station and travellers were told to leave.

Charlie Kenward ‏tweeted: "A man running up and down the station at Lewisham shouting he has a gun. Now been detained by the police."

And Ed Quigley wrote: "Armed police and at least 8 cars at an evacuated Lewisham Station.

"I'm told there is a civilian, not wearing much, dancing on the train track singing UB40."

A spokesman for British Transport Police confirmed they were called to the station at 8pm yesterday after reports a man was on the railway line.

They said a 32-year-old man was arrested 12 minutes later and is assisting police with their enquiries.