A train carrying furnace oil derailed and three of its wagons fell into a canal when a bridge gave way at Khitabchar of Boalkhali upazila yesterday, spilling oil into the water body and posing threat to the environment.

The canal flows to the Karnaphuli river, some 10 to 12 kilometres off the spot where the accident happened around 1:30pm. Experts fear the oil would soon spread in the river.

A thick layer of oil was floating on the canal water. The spilled oil was getting into nearby vegetable fields as well.

Railway sources said the train was carrying the oil for Dohazari Peaking Power Plant from the port city and each of the wagons was carrying around 25,000 litres of oil.

Three people, including the train's Loco Master Sahidullah and Assistant Loco Master Zafar, were hurt in the accident.

Train movement on the route was suspended.

The derailed tanks are expected to be salvaged by today, said Mozammel Haque, general manager of Railway's East Zone.

The oil spill in the canal, which flows into the Karnaphuli river about 12 kilometres off the accident scene, poses a threat to the river's biodiversity. Photo: Anurup Kanti Das

The bridge had long been in bad shape. A tender for its repair was floated recently, said railway sources.

Environment activist Muhammad Edris Ali, an associate professor of chemistry at Chittagong's Mohsin College, told The Daily Star that apart from killing the fish, the oil will affect the ecosystem and food chain in the area.

Prof Rashed un Nobi of Institute of Marine Sciences and Fisheries of Chittagong University said the incident would have a long-term negative impact on the local bio-diversity.

A man trying to clean up the oil spill. Photo: Anurup Kanti Das

Railway authorities have formed two committees to investigate the incident and asked them to submit reports within three days, said   sources.

Assistant Executive Engineer Abdul Halim and Senior Sub-assistant Engineer Akbar Ahmed Ferdous were suspended following the incident, said Chittagong Divisional Railway Manager Mafizur Rahman.

On July 9 last year, an engine and six furnace oil-laden tanks of another train veered off the tracks near Faujdarhat Railway Station in Sitakunda upazila.

That train too was carrying furnace oil for the Dohazari Peaking Power Plant.

One of the three oil wagons that fell into the canal. Photo: Anurup Kanti Das

Over 53,000 litres of furnace oil was lost in the incident and most of that oil spread to a nearby canal, locally known as Cadet Colleger Chhara. Later, the oil floated to the Bay of Bengal, around 2 kilometres off the spot. 

On July 30, 2013, three wagons of a train, each containing about 33,000 litres of furnace oil, derailed in Baruapara area of Boalkhali upazila while carrying furnace oil for the same power plant.