Four children were among at least seven people killed after a bus overturned in Russia, officials said.

The bus had been carrying children from the western city of Smolensk to the Kaluga region, south of Moscow.

It came off the road and overturned, with pictures showing the bus entirely on its roof in the snow.

“As a result of a road accident, seven people were killed, four of whom were minors. 24 people were taken to hospital,” the Kaluga region interior ministry said in a statement.

Most of the people taken to hospital were children, officials told Russian news agencies.

Footage released by local police showed firefighters carrying injured people on stretchers from inside the upside down bus.

Its windows were smashed and the bumper was hanging off.