A homemade bomb exploded at a packed London subway station during Friday morning rush hour, injuring at least 22 people. Police called it a "terrorist incident."
The attack on the District Line train at Parsons Green station was the fifth terrorist attack in Britain this year.
Scotland Yard said an improvised explosive device was used in the attack. London's Metropolitan Police counter-terrorism unit is investigating the terrorist incident. Police did not immediately provide any details on any suspects.
The ambulance service said at least one of the injuries was thought to be serious or life-threatening and most of the injuries were flash burns.
Passengers reported seeing people with burns to their faces and bodies after the "massive flash of flames" on the tube station.