Police have arrested a 23-year-old man they believe was behind the explosion at a London underground station which injured five people last night.

British Transport Police said Wednesday that they had detained the man on suspicion of “doing an act likely to cause an explosion to injure or damage property, and endangering safety on the railway.” He was not named.

The blast took place on Tuesday evening at Southgate underground station on the Piccadilly Line, and injured five people.

A police press release this morning said they believe the explosion was caused by “a faulty drill battery.”

It is not clear exactly what action by the suspect is believed to have led to the explosion.

Police described the incident as "minor" and do not believe it is linked to terrorism.