A double-decker bus veered off a mountain road and plunged into a ravine in southern Peru Wednesday, killing at least 44 people.
The bus tumbled 80 meters (260 feet) down a jagged slope from the Pan-American highway -- Peru's main motorway -- in the southern region of Arequipa.
Arequipa police chief General Walter Ortiz "confirms 44 deaths," the interior ministry said on its Twitter account, updating an earlier toll of 35.
Ortiz said 45 people were registered as passengers on the bus, but the ministry said this did not match the number of people killed or injured.
However, interprovincial buses in Peru frequently pick-up and drop-off passengers en route, resulting in discrepancies in the original passenger list.
Amid the confusion, the authorities did not specify the number of people injured. It was also not known if the driver was among them.
The accident happened in darkness around 1:30 am (0630 GMT). Rescue teams including firefighters and police "have been working since dawn, coordinating the transfer and care of the injured," Arequipa governor Yamila Osorio wrote on her Twitter account.
"The on-duty prosecutor is carrying out the removal of the corpses and experts from the police traffic accident investigation section are investigating the causes of the accident," traffic police chief Colonel Jorge Castillo said.
The injured were taken to hospital in the city of Camana, some 57 kilometers (35 miles) from the accident site near the town of Ocona.