"At 8:20 this morning at Parsons Green station there was an explosion on a tube train. We now assess that this was a detonation of an improvised explosive device," police counter-terror chief Mark Rowley told reporters.
People have published the photos and the video of the alleged device which went off.
In early June, a vehicle hit pedestrians on London Bridge. The vehicle with three suspects continued to drive from London Bridge to Borough Market, after which the suspects left the vehicle and carried out a stabbing attack at the market. The attackers were confronted by the police and shot dead within minutes.
In late March, four people were killed and many were injured after a vehicle drove into a crowd on London’s Westminster Bridge near the UK Parliament building. One man was later shot by police after he stabbed an officer inside the Parliament compound.