The mood has changed sharply at the summit of the G8 nations of the world's richest and most powerful nations.
By Steve Schifferes
BBC News economics reporter at the G8 summit in Gleneagles
The day had dawned clear and bright as thousands of journalists flooded into the media centre.
Prime Minister Blair said aid for Africa would help fight terrorism
Even the police were feeling jaunty after successfully containing the protest movements that threatened to breach summit security on Wednesday.
Hopes were high that a deal was close on helping tackle poverty in Africa.
Environmental groups, meanwhile, were gearing up for a fight over the wording of a communique - due to be released later on Thursday - on how the world can tackle global warming.
But within a few minutes the mood changed dramatically, as journalists and police alike crowded around large television screens to watch the unfolding events in London amid uncertainty and confusion.
There is now a sense of disbelief and horror, and a growing realisation that events which up to now had been the centre of the world's attention might now be far less important than the bombs in London.
Journalists covering the G8 summit were in shock
Some journalists have begun to pack their bags to return to the capital.
As speculation grew about the whereabouts of UK Prime Minister Tony Blair and his intentions, small crowds gathered around the UK delegation press office and the briefing rooms - but little hard information was forthcoming.
Meanwhile, police sirens and the sound of Chinook helicopters in the air emphasised the heightened security alert, while small groups of riot police gathered discreetly at doorways.
Tony Blair's statement at the G8 summit referred to a series of "terrorist attacks".
When Mr Blair first announced his initiative for Africa in a speech to the Labour Party conference in October 2001, he described it as an initiative designed to counter the threat of terrorism.
It is dreadful irony that as world leaders have come together to talk about fighting poverty, bombs are going off in the streets of London.