At least six children were killed and 20 injured when a school bus fell into a drain near Punjab's Amritsar town on Tuesday, police said.The children were students of M.K.D. DAV Public School in Neshta village near Attari, located close to the India-Pakistan border.Five of the 11 children who were taken to a private hospital in Chheharta were declared brought dead, Deputy Superintendent of Police Amandeep Kaur told reporters.She said the others have been admitted to the hospital's Intensive Care Unit.One more child died in another hospital.Around 40 students, a majority of them in the age group of seven to 12 years, were returning to their homes from the school in the bus.Eyewitnesses told the police that the bus got stuck on the bridge over the drain.As the driver tried to manoeuver it, the bus skidded off the road and hung precariously for a few minutes before falling into the drain, said an eyewitness.Locals said the administration had a tough time in extracting the victims from the bus, though villagers started the rescue operations before the authorities could reach the spot.