A major fire broke out in a laboratory at the Indian Institute of Technology, Madras, on Tuesday morning, The Hindu reported. The cause of the fire was not known immediately.

The fire, in the rocket and missiles laboratory, damaged explosives, propellants and sophisticated equipment. The facility was closed later.

Security staff and students of IIT Madras tried to put out the fire. Fire tenders from Guindy and Kotturpuram areas were also sent to the campus.

Some construction labourers and security staff first saw and reported the fire around 7.45 am. “While we were working here, we heard a loud blast-like noise,” A Silambarasan, a construction worker who witnessed the fire said. “We found thick smoke billowing from the first floor of laboratory. Fire engulfed the building and there was a blast three more times.”