''We have received information from the accident site that at least 20 persons were drowned when the bus fell into the canal,'' District Magistrate Provat Mishra said.

The police said the bus going from Babughat in Kolkata to Narayanpur swerved to the left to avoid hitting an autorickshaw and fell into the canal submerging both its exits.

Many of the injured, rescued by local people and the police from the bus, were taken to four local nursing homes.

Three of the bodies were fished out by divers of a 15-member team of BSF's disaster management unit which was scouring the waters to ascertain if any more bodies were stuck on the bed of the canal.

The police and local people rescued 30-35 injured persons, including three children, who were admitted to hospitals and nursing homes, the district magistrate said.

Nursing home sources said the condition of the injured children was serious.