India, Jan. 24 -- Authorities called off maintenance work on a key supply canal on Friday to restore normal water flow routes, officials said, after a spike in river pollution forced treatment plant shutdowns that have left large parts of the city without water for three consecutive days.

The supply disruption, which has hit neighbourhoods in north, west and northwest Delhi, was triggered by high ammonia levels in the Yamuna river, which resulted from planned repair work on the Munak canal.

Delhi Jal Board (DJB) officials said the crisis prompted an urgent decision to suspend maintenance and revert water flow to what is the regular channel.

"A temporary maintenance-related diversion was undertaken on a section of the canal network, for...