At least 19 people have been killed in a freak accident in southern India, after a container slipped off a truck and rammed into a passenger bus.

Police are investigating the incident, but officials say the container came off its hinges after one of the wheels of the truck had a puncture.

"There were about 48 people in the bus, and several are in a critical condition," an official told BBC Hindi.

The incident occurred around 3:30am local time (21:50 GMT), police said.

The bus was on a highway when the container slipped off the truck, which was in the opposite lane. It then rolled onto the other side, colliding with the bus. 

The Volvo bus, owned by the Kerala state transport corporation, was travelling from Bangalore city in the neighbouring state of Karnataka to Ernakulam in Kerala.

The district collector, Dr Vijay Karthikeyan, told BBC Hindi that the cause of the accident was still being investigated.

The driver of the truck is reportedly absconding. BBC