The incident occurred around 11:45am on Saturday, said Tejgaon Police Station OC Mazhar Hossain.
“A few people on their way to an event boarded a reserve bus carrying gas balloons,” he told bdnews24.com. “They exploded when someone on the bus lit a cigarette.”
Four were injured in the incident, said Mazhar.
The victims have been admitted to Dhaka Medical College Hospital, said DMCH police outpost in-charge Bachchu Miah.
