Twelve labourers living inside a wholesale snacks shop in Mumbai’s Andheri area died after they were trapped in a fire that engulfed the shop early on Monday.

The labourers were pulled out of the building and taken to Rajawadi Hospital in Ghatkopar, but were declared dead. “The bodies are completely charred,” said Dr Vidya Thakur, medical supritendent of Rajawadi Hospital. “We will know the exact cause of death following the autopsy.”

Officials said the fire brigade got a call at 4.17 am. Three fire engines were sent to the shop and the fire was doused, but a loft in the shop collapsed because of the heat and smoke. The fire department said the workers were sleeping on a loft built inside the shop and were trapped. “The loft collapsed because of the extreme heat and smoke inside. This could have killed the workers,” said an officer from the fire department.

The department and the Sakinaka police station are looking into the cause of the fire.

“We are finding out if the shop had the required permissions,” said ward officer Ajitkumar Ambi, but added that the focus was on rescuing people. Ambi said workers are allowed to live inside such shops, but with permission.