London -  British Transport Police have arrested a 23-year-old man in connection with a small explosion at a London Underground station that injured five people.

The police say in a statement Wednesday that the man “was arrested on suspicion of doing an act likely to cause an explosion to injure or damage property endangering safety on the railway.”

They said the explosion on Tuesday night at the Southgate station in north London was believed to be caused by a faulty drill battery and did not seem to be related to terrorism.

The man was released pending further inquiry.