Natasha Grzincic in London. Following explosions that have paralysed London, prime minister Tony Blair announced that the G8 leaders have no intention of cancelling the summit.
In a live national broadcast from Gleneagles Hotel at 12.05GMT, Blair said it was the will of the G8 leaders to carry on as usual.
'All the leaders share our determination to defeat this terrorism,' said Blair.
He called the explosions 'particularly barbaric' on the eve of making crucial decisions to help eradicate poverty in Africa and make progress on climate change.
During Blair's speech, riot police were seen to be 'padding up' outside the Stirling campsite.
The prime minister will be flying to London shortly for the day, then returning to Gleneagles in the evening.
A large number of casualties were reported after at least seven explosions on the London Underground network. According to the BBC, a police spokeswoman confirmed there had been two deaths at Aldgate and UK home secretary Charles Clarke said the explosions caused 'terrible injuries'.
Arab sources told the BBC the blasts are the work of al-Qaeda.
Explosions have been reported at Edgware Road, King's Cross, Liverpool Street, Russell Square, Aldgate East and Moorgate, as well as on a double-decker bus in Tavistock Square, but the situation is still very 'confused', according to London's Metropolitan Police commissioner Sir Ian Blair. He urged people to stay where they were and not to call emergency services unless for life-threatening reasons.
Mobile phone networks are prioritising emergency services, which is causing problems for normal users.