An unusually loud explosion rocked the Motijheel area, the commercial district of Dhaka, which was fortunately almost empty due to Durga Puja, while the subsequent blaze immediately engulfed the upper three floors of the building after it sparked at the second floor, they added.
"The explosion broke windowpanes of the state-run Bangladesh Chemical Industries Corporation Sadan building, scattering objects like heavy air conditioners and computers 50 yards away from the building," police sub-inspector Tazul Islam told PTI at the scene.
"Six people who were inside the building were critically injured and one of them later succumbed to his wounds after being rushed to a hospital," Islam said.
"The causalities could be much higher had it occurred during the normal office day at the busy area," a journalist, who witnessed the rescue efforts, said. Nine fire tenders were rushed to the spot and the fire was extinguished after two hours, but witnesses said the blaze had destroyed almost everything.
Fire brigade officials and police could not immediately ascertain the cause of the blast. An investigation would be carried out to ascertain if the blast, which comes days after security was stepped up to counter any possible terror attacks in major government complexes, was an act of sabotage, security officials added.