Rescue workers said the drivers of both vehicles were killed in the crash
At least 20 people have been killed in a crash between a bus and a petrol tanker in south Russia, officials say.
The accident happened on a highway near Samarskoye, south of Rostov-on-Don.
Rescue workers are still at the crash site and officials say the death toll may rise. Nine injured people are in serious condition at nearby hospitals.
The bus was travelling from Krasnodar to Volgodonsk when it hit the tanker head-on. The weather and visibility were reportedly good at the time.
Rescue workers said that, judging by the position of the vehicles on the road following the crash, they believed the tanker had crossed into the oncoming lane. An investigation has been begun.
The collision did not cause a fire to break out, they said. It was not immediately clear if the tanker had been carrying a full load of petrol.
The ministry of emergency situations for the Rostov region said there had been 27 passengers on board the bus.
The drivers of both vehicles were killed, a member of the rescue team told the Interfax news agency.