The reports said the bus was travelling from the eastern city of Iğdır to İstanbul, the northwest of Turkey.

The accident took place 35 kilometers from Ardıç village, located in Osmancık town of Çorum. The number of passengers the bus was carrying during the accident has not been determined.

The cause of the crash is not known, but an initial report suggests a combination of slippery ground and excessive speed may have led to the accident.

Acting on a tip from drivers travelling on the motorway, a number of ambulances rushed to the scene from the three nearby districts; Osmancık, Kargı and Dodurga.

Fire crews immediately responded to the scene and used cutting equipment to rescue some passengers trapped in the wreckage .

The injured were taken to Osmancık hospital for further treatment after paramedics administered first aid on the spot. Four are in serious condition at the hospital.