Five firefighting units are at the scene carrying out their rescue efforts, Dhaka Tribune quoted Fire Service Officer-in-Charge (Media Cell) Md Shahjahan Shikder as saying.
He said the explosion happened in the Alubazar area of Fulbaria in the capital.
Twenty of the injured were taken to Dhaka Medical College Hospital, said DMCH police outpost Inspector Bacchu Miah, adding that all of them were receiving treatment at the hospital's emergency unit.
The cause of the explosion could not be known immediately.