London on full terror alert

London is today on full terror alert amid growing fears that the Madrid train massacre was the work of al Qaeda.

Senior Scotland Yard officers are urgently reviewing security measures which are already in place around potential targets such as train and Underground stations.

Met Commissioner Sir John Stevens condemned the Madrid bombings as a " criminal outrage" and said London was already on high alert. Massive security is in place around potential Westminster targets while covert and uniform patrols are deployed around the transport system.

Police are using scanning devices to detect suicide bombers and hidden cameras to check for suspicious cars.

The alert came after an al Qaeda-linked group claimed responsibility for yesterday's attacks, which killed 198 people and left more than 1,400 injured -and warned that Britain and America were next on the target list.