Water has returned to scores of properties and businesses after a burst water main yesterday – but workmen still have no idea how long the road will remain closed.

Ham & High: Thames Water does not yet know how large the chasm isThames Water does not yet know how large the chasm is (Image: Archant)

Engineers worked through the night to restore water to some 64 properties in Flask Walk, Hampstead, and finally had the taps running again by 3.45am this morning.

The burst pipe led to the discovery of a void under the tarmac, which may have made the road unstable.

Thames Water does not know how long the repair job will take, but the road may remain closed to traffic for weeks.

A spokesman for the utility firm said: “It’s now a case of getting the repairs done as quickly and safely as possible.

“Communication is key, and we will be speaking to all the residents regularly to keep them informed.”