Hawzah News Agency - (Narayanganj - Bangladesh) - A suspected gas explosion tore through a Bangladesh mosque killing 13 people and dozens suffered life-threatening burns, officials said Saturday (Sep 5).

Worshippers were at Friday evening prayers when the blast sent a ball of flames through the mosque in the central district of Narayanganj, emergency services said.

Investigators suspected a spark from an air conditioner - which came on after a power cut - set off the gas.

"Leaked gas entered the mosque," Narayanganj fire chief Abdullah Al Arefin told AFP.

"When they shut the windows and doors and switched on the air conditioners there was an electricity spark that led to the explosion inside the mosque."

All six air conditioners in the mosque exploded during the incident, he said.