A police press conference on 12 July provided further details on the progress of the investigation. Investigators focused on a group of four men, three of whom were from Leeds, West Yorkshire.
On July 7, 2005, all four travelled to Luton in Bedfordshire by car, then to London by train. They were recorded on CCTV arriving at King's Cross station at about 08:30 am.
The twenty-two year-old attended Leeds Metropolitan University, where he studied sports science and was an avid cricket player and fan.
He had always lived in the Beesten area of Leeds. His family includes a younger brother and two sisters.
Tanweer also went to Pakistan to study Islam and had taken part in the Hajj. In 2004, he was arrested for detonating a bomb on a train between the Aldgate and Liverpool Street stations which killed at least seven people - including himself - and injured more than 100 others.
Hussain, 19, lived with his family in the Leeds suburb of Holbeck all his life. He left high school in 2003, without graduating.
Hussain was arrested for shoplifting in 2004. On July 7, he told his parents he was going to London to visit friends.
When he didn't return, his parents reported him to the police as missing. His driver's licence and cash cards were found in the wreckage of the double-decker bus, where at least 13 people died.
Mohammed Sidique Khan
Khan, 30, born in Pakistan, was the father of an eight-month-old girl. He originally lived in the same area of Leeds as Tanweer, but moved to Dewsbury in West Yorkshire.
He had been a teaching assistant at a primary school since 2002. Documents belonging to Khan were found in the debris of the Edgware Road subway blast, where at least seven people died.
The 19-year-old Jamaican had converted to Islam and changed his name to Jamal Lindsay.
He had been attending after-school classes to improve his knowledge of Islam. He was married and had a 15-month-old child.
It's believed Lindsay set off the bomb near the King's Cross tube station where at least 26 people were killed.