Seems the No. 30 bus bomber called his accomplices shortly before his bomb exploded. But they were already dead.

He did not try to contact anyone else, which suggests there was no “mastermind” or that he did not want to implicate them, said Daniel Sandford.

The most likely explanation was that he had tried to board the Northern Line, but it was closed, so when things started to go wrong he tried to phone his co-conspirators, he added.

Terrorism expert Michael Clarke, of King’s College, said the calls showed Hussain was in a panic and probably rang his accomplices to make sure their bombs had exploded.

The bomb attacks killed 52 people and injured over 700. Three of the four July 21 bombers are in UK custody with the fourth awaiting extradition from Italy. Another 11 people have also been arrested.