A THREAT HAS BEEN MADE.

AN ULTIMATUM DELIVERED.

INNOCENT PEOPLE ARE IN MORTAL DANGER.

8am: an explosion blasts through a cafe in central London.

Minutes later a call is made to a local radio station:

We've just detonated a bomb. Another will explode shortly.

The British Government has until 8pm tonight to meet all our demands, or a far greater attack will take place somewhere in the country that will bring fire down on all your heads.

You have been warned...'