Twenty people were killed in southern Russia on Friday when a passenger bus collided with a truck, Russian news agencies reported, citing emergency officials.

The accident occurred when the bus collided head-on with a fuel truck in the country's southern Rostov region, around 1200 kilometres (750 miles) south of Moscow, Interfax and ITAR-TASS said.

"Twenty people died in the road accident, rescuers are continuing work at the scene of the tragedy," said a spokesman for Russia's Emergency Situations Ministry, Interfax reported.

ITAR-TASS reported that 19 people had died at the scene of the crash outside the village of Samarskoye, and that another person had died in hospital.