A man was arrested after a small blast at a London Underground station believed to have been caused by a faulty drill battery, British Transport Police (BTP) said.

The 23-year-old, from Enfield, north London, was held on suspicion of doing an act likely to cause an explosion to injure or damage property, and endangering safety on the railway.

He has been released under investigation pending further inquiries.

Five people suffered minor injuries after the explosion at Southgate Tube station, BTP said.

Officers were called to reports of an incident shortly after 7pm on Tuesday.

A man on a "packed" escalator said some people had been "trampled" in the commotion.