About 2,000 people were evacuated from their homes in Stepney after the discovery of the unexploded bomb.

Workman Richard Beadle stumbed across the bomb

Experts had to cut holes in the bomb's casing before steaming the explosive out. The controlled blast was intended to deal with any explosive that may have been left.

Major Rob Piper from the army disposal unit said the difficulty was in keeping the temperature high enough to melt the substance, but not so high as to cause an explosion.

A spokesman for the Metropolitan Police Force said it was likely that similar incidents would occur in the future.

He said: "Given the amount of metal that was rained down on London during the Blitz - it could happen again in the future."

Tower Hamlets Borough Council said that residents could move back into their homes soon after the controlled explosion.

Not all of the 2,000 residents asked to evacuate their homes complied

The Council had set up two emergency refuge centres at nearby schools, even though a number of residents did not want to leave their homes.

Leader of the council, Julia Mainwaring, said that they moved out most of the people.

She said: "Some people were determined they were not going to leave. We have given them advice to stay away from their windows."

She added that some residents had lived through the war and had been present when the bombs were falling and perhaps did not think the situation was overly dangerous.