Prosecutors are expected to open their case on Wednesday against three men accused of conspiring with the July 7 suicide bombers who carried out attacks on London's transport system in 2005.

The men were the first to be charged over the co-ordinated morning rush-hour attacks on underground trains and a bus, killing 52 commuters and injuring more than 900 others.

The bombers, Mohammad Sidique Khan, Shehzad Tanweer, Jermaine Lindsay and Hasib Hussain, also died during the most deadly peacetime attacks by militants in the British capital.

Mohammed Shakil, 31, Sadeer Saleem, 27, and Waheed Ali, 24, are facing trial at Kingston Crown Court, accused of scouting targets for the bombers.

Prosecutors allege that between January 1, 2004, and July 8, 2005, they conspired with the four suicide bombers and others unknown to cause explosions likely to endanger life or cause serious harm and injury.

The group, all from Beeston, Leeds - where three of the four suicide bombers grew up - have pleaded not guilty to the single charge.

The trial is expected to last four months.