At least 12 labourers were killed and nine were injured on Wednesday after a portion of a chemical warehouse collapsed following a huge explosion on Piranha-Piplaj Road, an industrial area located on the outskirts of Ahmedabad city, NDTV reported.

A powerful explosion in the warehouse in the morning destroyed the structure and triggered a blaze in adjacent godowns where labourers were packing ready-made garments, officials told PTI.

The city’s fire brigade was called in and by the end of a nine-hour long rescue operation, the personnel had pulled out 12 bodies and rescued nine people from the rubble. The injured were shifted to the Ahmedabad Municipal Corporation-run LG Hospital, said chief fire officer MF Dastur.

“We pulled out 12 dead bodies from the debris,” Dastur told NDTV. “We also rescued nine people alive. The fire was doused within 30 minutes, the operation was mainly about rescuing people trapped in the rubble.” He said that a team of the National Disaster Response Force assisted in the rescue operation.

Prime Minister Narendra Modi condoled the death of the labourers. “Anguished by the loss of lives due to a fire in a godown in Ahmedabad,” he tweeted. “Condolences to the bereaved families. Prayers with the injured. Authorities are providing all possible assistance to the affected.”

President Ram Nath Kovind also offered his condolences to the families of the workers.