A group calling itself 'The Secret Organization of
al-Qaeda in Europe' posted a claim of responsibility for the blasts, saying they were in retaliation for Britain's involvement in Iraq and Afghanistan. The Web statement, republished on the site of the German magazine Der Spiegel, could not be immediately
"We do not know who or what organisations are responsible for these terrible criminal acts," Britain's Home Secretary Charles Clarke said.
Mainline stations were closed and Tube and bus services were cancelled across the city.
Metropolitan Police Commissioner Sir Ian Blair said there had been at least six explosions, but said the picture was still 'very confused'.
Clarke said there have been 'terrible injuries' from a 'number of dreadful incidents' across London, and 'we advise people not to make unnecessary journeys in London at this stage in order to help emergency services deal with the current situation'.
The scene at Tavistock Square, London, with debris on the ground and bloodstains on the wall, following a bus explosion there.
AP Photograph: Jane Mingay