A police spokeswoman said cause of deadly accident was being investigated.

At least 19 people have been killed after a bus plunged off a bridge onto a frozen river in Siberia on Sunday, authorities said.

A tyre on the bus, which had 43 passengers and a driver on board, burst as it was crossing the bridge over the Kuenga river in eastern Siberia’s Zabaikalsky region.

“Nineteen people died and 21 received various injuries,” the office of the governor of the Zabaikalsky region said in a statement.

Two helicopters with medics were dispatched to the scene. The bus was travelling from Sretensk to Chita – 6,320km (3,927 miles) east of Moscow, according to Russia’s emergencies ministry.

Russia’s Investigative Committee, which probes serious incidents, said it had opened a criminal inquiry into a possible violation of traffic safety rules.

Road accidents are common in Russia, often due to alcohol, the poor state of roads and failure to observe traffic rules.

However, the number of road deaths has gone down in recent years. According to the country’s traffic police 18,214 people died in road accidents last year.