People gather around two passenger trains that collided in the city of Shahroud, in the north-central province of Semnan, killing dozens people Reuters

At least 31 people have been killed in Iran's Semnan province, after two passenger trains collided at a train station 150 miles east of Tehran.

At least four of those killed were railway employees aboard the two trains. State news said the accident took place in freezing temperatures and carried images of rescue teams working to clear the burning carriages.

The governor of Semnan Mohammad Reza Khabbaz said the accident was being investigated as authorities worked to ascertain its exact cause. He confirmed the death toll in the accident, adding the parked train was not in the station but on a main line.

At total of 80 individuals were injured in the accident, Pir Hossein Kolivand, who runs Iran's emergency department, said. They have been taken to hospital for treatment. Helicopters and ambulances were sent to the scene, the associated press reported.

There are 17,000 deaths In Iran ever year as a result of road traffic accidents. The high rate is attributed to a number of factors including poorly enforced traffic laws, old vehicles without up-to-date safety standards and inadequate emergency services.