More than 30 people have been killed in a bus crash on a mountain road in Bolivia, police say.

The vehicle plunged almost 800m (2625 ft) into a ravine the southwestern district of Yocalla, an officer said.

Fourteen people were also injured, including four children, an official from a local hospital said in a video.

Bolivia has notoriously dangerous roads, particularly in mountainous areas.

The accident happened between the cities of Potosí and Oruro, police said.

Officials believe that the crash could have been caused by speeding, with the driver “unable” to control the bus, police colonel Victor Benavides told the AFP news agency.

This is believed to be the most serious road accident reported in the South American country so far this year.

Local news outlet Unitel reported that several of those injured were in a serious condition.

Deadly road accidents are common in Bolivia.

Last month, 19 people were killed when another bus came off a road, also near Potosí.

Road accidents kill an average of 1,400 people every year in the country of about 12 million inhabitants, according to government data.