The burst pipe affected 20 business properties. Pic from Tom Dowman

Twenty business premises were flooded and supplies to about 700 homes cut off when the pipe in Maida Vale ruptured on Friday morning.

Thames Water said water levels had subsided and supplies had been restored to the majority of affected properties.

Engineers were assessing the damage to the pipe and road surface, both of which may have to be replaced.

A spokeswoman for Thames Water said: "We have given ourselves a week but we hope to have it reopened before then."

Homes evacuated

The A5 Maida Vale has been closed both ways between Elgin Avenue and Blomfield Road and there are diversions in surrounding roads.

Emergency services were alerted to the leak, at the junction of Maida Vale and St John's Wood Road, just after 0600 BST.

London Fire Brigade pumped water from the area as engineers worked for five hours to stop the leak.

Thames Water said 20 commercial properties were flooded and they received calls from 700 homes who had lost their water supply.

A spokeswoman said the majority of homes now had their water supply back on and about 30 people evacuated from their homes, due to loss of electricity, had returned during the afternoon.

Danger of collapse

One local resident said the main had burst before.

"This is the third time that this has happened, exactly the same spot. The whole of Edgware Road is out of action...traffic chaos, then the same again," he said.

A Thames Water spokeswoman said a vast city-wide project was under way to replace London's 150-year-old water mains, and that this section would now be targeted for renewal.

London Fire Brigade said the water may have undermined the road and there was now a danger it could collapse.