Police have set up a 400-metre exclusion zone in Docklands after the discovery of an unexploded bomb dating back to World War Two.
The bomb, believed to be a 'Doodlebug', was unearthed on a building site on the Isle of Dogs.
Marsh Wall was closed both ways closed due to the incident, between Limeharbour and Millharbour.
The Docklands Light Railway, which was carrying visitors to an air race near the Dome, was not closed.
London's docks were a major target for German bombers during the 1939-45 war and many unexploded bombs have been discovered in the area since.
V-1s (Doodlebugs) were flying missiles that had enough power to fly over the Channel and were capable of destroying two to three houses.
They were also known as 'buzz-bombs' because of the distinctive drone of their engines.
But when they cut out, terrified people on the ground ran for cover as they knew a bomb was falling from the sky.
Police expect the exclusion zone to remain in place until Sunday, when it may be extended while disposal work is carried iout.