The bombers: Hasib Hussain, Germaine Lindsay (dark cap), Mohammad Sidique Khan (light cap) and Shehzad Tanweer
Police have released a CCTV image of the four London bombers as they set out from Luton on their bombing mission.
They have also confirmed the names of all four men for the first time.
Mohammad Sidique Khan, 30, Germaine Lindsay, 19, Hasib Hussain, 18, and Shehzad Tanweer, 22, were pictured in Luton at 0720 BST on Thursday 7 July.
Three bombs exploded on the London underground at 0850 BST, and one on a bus at 0947. Fifty-five people died, including the four bombers.
The picture was released in an attempt to find out more about their final movements.
It is thought Hussain was responsible for the bus bombing, in which 13 people died, Khan the Edgware Road blast that killed six people; Tanweer for the Aldgate blast, which killed six, and Lindsay for the Russell Square explosion where 26 people were killed.