(CNN) -- A bus crashed into the side of a mountain Tuesday in western Bolivia, killing at least 13 people and injuring another 26, the government news agency reported.
The driver lost control of the bus, which gained speed and smashed into rocks on the side of the road, said police official Victor Hugo Ona.
The bus left the city of La Paz with 28 passengers but was later found to have 41 passengers and excess baggage, Ona told the state-run Agencia Boliviana de Informacion.
Among the dead were seven men, four women and two minors, said Jose Villarroel, another police official.
At least 19 of the injured were hospitalized. Bus driver Pedro Limachi, 45, was listed among the injured being treated at the Hospital Arco Iris in La Paz.
The bus was operated by the Flota Yunguena transit company.
Bolivia's mountainous roads often prove fatal. A bus crash in central Bolivia in June left 28 dead and 44 injured after an apparent brake failure, police said at the time. That bus, which plunged into a ravine, was owned by the El Dorado company.
A January bus accident killed 22 people. And 19 people died and 26 were injured in August 2009 when a bus plunged off a mountain road.