At least four people were killed and 22 injured when a bus plummeted into a ravine early Sunday morning near the southern Bolivian town of Monteagudo in Chuquisaca Department, local authorities have reported.

According to a preliminary report, the vehicle swerved off the road while taking a curve at excessive speed, though ultimate responsibility has yet to be determined, according to Chuquisaca Prosecutor Mauricio Nava.

Police and Public Ministry personnel were dispatched to the scene to assist the injured.

(With input from Xinhua)