A massive fire in Bangladesh that raced through a six-storey building home to restaurants where many families with children were dining has killed at least 45 people and injured dozens, the health minister said on Friday.

Fire authorities said a gas leak or a stove could have caused Thursday’s blaze in the capital, which spread quickly after breaking out in a biryani restaurant, and was only reined in following two hours of effort by 13 units of firefighters.

Hospitals are treating 22 people with burn wounds, Health Minister Samanta Lal Sen told reporters.

“All 22 people ... are in critical condition,” Sen said after a visit to the Dhaka Medical College Hospital.

Prime Minister Sheikh Hasina expressed shock and sorrow over the incident, ordering officials to provide swift treatment for the injured.

One survivor, Mohammad Altaf, recounted his narrow escape from the blaze that killed two colleagues.

“I went to the kitchen, broke a window and jumped to save myself,” he told reporters, adding that a cashier and server who urged people to leave during the first moments had died later.

Firefighters used cranes to rescue people from the charred building, said fire officials, who were still working to clear debris and stamp out any remaining embers.

Relatives gathered at the hospital early on Friday to receive the bodies of the dead, with some mourning outside the emergency department.