At least 20 people died and 17 others are in critical condition after suspected air conditioner explosions during Friday night prayers at a mosque near Bangladesh’s capital, officials said.

A 7-year-old boy, the muezzin and the imam were among the deceased in the accident in the city of Narayanganj, while others are getting treatment at the Sheikh Hasina National Institute of Burn and Plastic Surgery in Dhaka, the capital.

Bangladesh Fire Service and Civil Defense duty officer Ershad Hossain confirmed with Anadolu Agency the death toll, adding the wounded sustained severe burn injuries.

Meanwhile, three committees have been formed to investigate the incident, including one by the fire service, Hossain added.

The patients in critical condition sustained burns to the trachea, Anayet Hossain, deputy assistant director of the Bangladesh Fire Service and Civil Defense, told Anadolu Agency.

He quoted a doctor at the hospital who said the injured suffer from burns covering 30% to 70% of their bodies.

President Abdul Hamid, Prime Minister Sheikh Hasina and the Religious Affairs Ministry among others expressed deep sorrow and ordered support for the victims and proper investigation of the incident.

The State Minister for Power, Energy and Mineral Resources Nasrul Hamid in an immediate statement instructed all the power distribution companies to check the power connections and condition of air conditioners of mosques, temples and other religious institutions in the area covered by them.

An investigation into the blasts has already begun, he added, saying the primary cause could not be confirmed but the explosions were caused by the air conditioners.

Local The Dhaka Tribune reported that a pipeline passes underneath the mosque and that gas had leaked and accumulated inside as the mosque windows were closed.

The explosions were probably triggered by sparks when someone tried to switch on or off the air conditioners or fans, it added, quoting a local official saying the mosque had recently filed a complaint over the gas leaks.