A tube terrorist injured 22 in a bucket bomb blast in London. The device exploded at 8:20 a.m. on a District Line train leaving the Parsons Green station.

The incident is now being treated as terrorism-related, the Metropolitan Police said. Armed police are at the station and surrounding homes are being evacuated, according to independent.co.uk.

Downing Street said Theresa May was “receiving regular updates’’. The PM was due chair a meeting of the Government’s emergency Cobra committee this afternoon.

Five Metropolitan police vans arrived on the scene at about 9.40am along with a BTP command van. A 100-metre cordon was erected around the station, theguardian reported.

The incident is the fifth terrorist attack in the UK this year, following incidents at Westminster, London Bridge, Manchester and Finsbury Park in north London. The UK terrorism threat level remains at severe, meaning an attack is highly likely.