Four workers were killed as an oil tank of a factory exploded while repairing a line at Bhawanipur in Sherpur upazila of Bogura on Thursday.

The deceased were Md Imran, Mohammad Syed, Md Rubel, and Md Manir, residents of Syedpur Officers Colony in Nilphamari.

The accident occurred at Majumdar Product Limited around 2:15 pm when the oil tank exploded during welding work of the pipeline, leaving four workers injured, said Rezaul Karim Reza, officer-in-charge of Sherpur police station.

They were taken to Shaheed Ziaur Rahman Medical College and Hospital where doctors declared them dead.

The explosion occurred with a big bang as a spark of fire from the welding machine fell into the oil tank.