Explosions have been reported at six Underground stations and on one bus.

Amnesty International Secretary General Irene Khan said:

'Our thoughts and sympathy are first and foremost with those who have become the victims of senseless violence this morning.

'Our common vulnerability makes us all a part of this tragedy, but our common humanity and conviction in human rights must convert the sense of fear into solidarity and action.'

Amnesty International said that deliberately attacking civilians can never be justified. Targeting commuters going about their daily business shows complete contempt for the most fundamental principles of humanity.

To the extent that these bombings are part of a widespread attack on the civilian population of Britain in furtherance of an organisation’s policy, they would constitute a crime against humanity.