The injured were taken to a hospital in nearby Chakwal for treatment [EPA]

A bus carrying students on a school trip crashed on the Lahore-Islamabad motorway through the Kalar Kahar Salt Range of Pakistan's Punjab province, killing at least 37 and injuring 70.

According to Motorways police, the students from Millat Grammar School were driving from Faisalabad to Kalar Kahar, which is 160km south of the capital Islamabad, after an outing at the popular tourist attraction.

On their way home, their bus had an accident after its brakes failed, causing the vehicle to fall into a ravine.

Pictures from the scene showed the mangled wreckage of the bus and debris scattered over the ground.

Police said two teachers, including the vice-principal of the school, also died in the crash, and that the injured were taken to the district headquarters hospital in Chakwal.

Pakistan has one of the world's worst records for deadly traffic accidents, blamed on poor roads, badly maintained vehicles and reckless driving.

At least seven children were killed in June when their bus fell into a canal in Pakistan-held Kashmir.

The district administration of Faisalabad province has announced the day off for all schools, government and semi-government offices due to the bus accident.

Source: Al Jazeera and agencies