The death toll from an oil tanker fire in Afghanistan’s high-altitude Salang Pass tunnel has risen to 31, an official said Monday, with dozens more suffering burn injuries. The incident occurred late Saturday in Parwan province, north of Kabul, leaving travellers on both sides of the mountain pass stranded. At least 31 people were killed and 37 were injured in the incident, Sharafat Zaman Amar, spokesman for the public health ministry, told AFP on Monday. The toll was expected to rise further, he added. The tanker overturned and caught fire in the tunnel, setting many other vehicles ablaze, officials said earlier. The Salang Pass, one of the highest mountain highways in the world at an altitude of around 3,650 metres (12,000 feet), was built by Soviet-era specialists in the 1950s and includes a narrow 2.6-kilometre tunnel. The pass runs through the Hindu Kush mountain range that connects the capital Kabul to the north. Hailed as an engineering feat upon completion, the Salang Pass is often shut for days because of accidents, heavy snowfall and avalanches during the winter. In 2010, avalanches killed more than 150 people along the treacherous highway.