Overcrowded vehicle, including passengers travelling on its roof, plunges over a cliff, killing at least 30 people.
Dozens of Argentine police have been killed in a bus accident on Monday in the northern part of the South American nation, news reports said.
The Associated Press news agency reported at least 41 officers were dead.
Authorities say the crash happened early on Monday while a convoy of three buses with police officers was travelling near Salta, a city about 1,500km north of Buenos Aires.
Angel Marinaro, civil defence director for the province, told local station TN that the driver of one of the buses lost control as the convoy was crossing a bridge.
The vehicle flipped and fell off the bridge, landing about 20 metres below in a dry riverbed. Television images showed an overturned bus and rescue crews working at the scene.
Authorities say the bus was carrying about 60 people, and survivors were being taken to a nearby hospital.
Gustavo Solis, mayor of Rosario de la Frontera, told the AFP news agency at least 20 people died.
The cause of the predawn accident was unclear, said Solis. Some people remain trapped in the wreckage of the bus and the death toll could rise, he said.