London blasts take a heavy toll

Four blasts ripped through London during rush hour on Thursday morning, killing at least 33 people and disrupting a summit of Group of Eight leaders in Scotland in attacks Prime Minister Tony Blair called "barbaric."

Security sources told Reuters there were fatalities at all four bomb sites, and Sky Television said at least 45 people had been killed. A further 150 were seriously wounded, and hospital staff said some were unlikely to survive.

Britain has been key ally of the United States in its war in Iraq, where al-Qaida is waging a bloody insurgency. The blasts occurred one day after London was awarded the 2012 Olympics.

"If what we are looking at is a simultaneous bombing, and it does look like that, it would very certainly fit the classic al-Qaida methodology which centers precisely on that: multi-seated hits on transport and infrastructural targets," said Shane Brighton, intelligence expert at the Royal United Services Institute for Defense.