The face of British policing has been changed forever by the revelation that suicide bombers have struck for the first time in this country.

Armed officers responding to alerts will follow a "shoot-to-kill" policy, while further security precautions will be taken in buildings regarded as prime targets. It is also understood that fresh advice has been circulated to chief constables in the wake of last Thursday's atrocities, who in turn have passed the information to front-line officers.