At least 15 people were killed and several others injured in an explosion in a crowded market area in Bangladesh’s capital Dhaka on Tuesday, a local fire service official said.

The blast occurred inside a seven-storey building, causing heavy damage to two floors, the official added.

“There were several shops selling sanitary ware and household goods. A bus standing on the opposite side of the building was also damaged in the blast,” fire service official Dinomoni Sharma said.

The cause of the blast was unclear, Sharma said, adding that the death toll could rise as rescue operations were ongoing.

Images from the scene showed extensive damage to the building and nearby structures, with items that were once inside the shops piled up on the street. Some pedestrians were hurt by falling rubble and broken glass.

Kamal Ahmed, who was among those injured in the explosion, told local media he was shopping on the sidewalk when he heard a loud bang.

“Hearing the sound, I fell. Then I saw smoke covering the whole area. No buildings are visible. All the people are running,” he said.

It follows the death of three people in an explosion in Dhaka on Sunday

On Sunday, three were killed in a suspected gas explosion in Dhaka. On Saturday, seven people were killed and several injured when a fire broke out following an explosion at an oxygen plant in southeastern Bangladesh.