At least 37 people were killed and dozens injured in Peru when a bus plunged into a 200m (650ft) deep ravine after a head-on collision.

The incident happened in the early hours of Wednesday morning on a “rugged” stretch of the Pan-American Highway that connects Peru with Chile in the country’s southern region of Arequipa.

Local media say the bus was carrying 60 passengers when it smashed into a pickup truck on a curve, careered off the road and fell down to the banks of the Ocoña River.

Bus crashes are common in Peru, especially at night and on mountain highways. This is often due to poor road conditions, excessive speed, and lack of safety signage.

The bus, operated by the Llamosas company, was heading from Chala, a town in Caraveli province, to Arequipa.

Both drivers reportedly survived the crash, which happened at kilometre 780 of the Pan-American Highway South.

Pictures from the scene of the crash show the wrecked bus at the bottom of a steep ravine – its windows completely shattered, bodywork badly damaged and roof caved in.

Waldor Llerena, Ocona’s district mayor, told radio station RPP that the terrain around the crash site is “very rugged”, and the area had a history of similar deadly accidents.

Thirty-six people died at the scene and another person later died in hospital, Walther Oporto, Arequipa’s regional health chief told local media, citing firefighters at the scene of the crash.

Health officials told RPP that 25 people – including three minors – are being treated in a local hospital for their injuries.

An investigation into the incident is underway and the driver of the pickup truck has been detained, the Public Prosecutor’s Office said in a statement.

In 2022, more than 3,300 people died in traffic accidents in Peru, official figures suggest.

Stretching from Alaska to the pencil tip of Argentina, the 48,000km-long Pan-American Highway holds the record for the world’s longest road navigable by motor vehicle.