23-year-old man has been arrested after an explosion at Southgate underground station sparked panic and left five people injured.
Police said the man, from Enfield, was detained on suspicion of doing an act likely to cause an explosion to injure or damage property following the incident on Tuesday evening.
He has been released under investigation as enquiries continue into the explosion which is believed to have been caused by a faulty drill battery.
Witnesses described commuters fleeing for the exit after a massive bang and quick burst of flames in the north London station just after 7pm.
A man on a packed escalator said some people had been trampled in the commotion.
A British Transport Police spokesperson said: Enquiries continue this morning into a small explosion at Southgate Underground station last night.
The incident, which left five people with minor injuries, is believed to have been caused by a faulty drill battery.
A 23-year-old from Enfield was arrested 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 enquiries.
London Ambulance Service said two people had been taken to hospital and three others were treated at the scene in north London for minor injuries.
A spokeswoman said: We have treated three patients at the scene for minor injuries and have taken two people to hospital.
British Transport Police stated yesterday that the incident was not believed to be terror-related.
James Ayton, 34, from Southgate, was on the packed escalator when he saw a quick burst of flames at the top and said everyone legged it.
He said there had been a very rapid whooshing sound.
He added: A few people got trampled on the escalator. There was screaming.
An old woman got trampled on. I had to carry a woman up the stairs. I think she was in shock to be honest. She couldn’t walk, shaking.
Mayor of London Sadiq Khan praised emergency services for a swift and professional response to the incident.