Parsons Green station has re-opened after a bomb was detonated on a London Underground train, injuring 29 people. The improvised explosive device sent a fireball through a packed train carriage during Friday morning rush hour. Britain is currently on the highest terror alert, meaning another attack is expected imminently, and a manhunt is under way for the "suspects".
All you need to know about what is known - and what is not - about the bomb attack on a London Tube train.
The installation of CCTV cameras on the the Tube could play a key role in finding the perpetrator of the Parsons Green explosion.
Theresa May rebuked the US president after he implied the London tube blast was carried out by suspects "in the sights" of Scotland Yard.