Six labourers were killed and 10 others injured after the wall of an under-construction factory collapsed in Rajasthan's Jodhpur district on Tuesday evening, police said.
Search and rescue operations are underway as some more labourers are feared trapped under the debris, they said.
Chief Minister Ashok Gehlot expressed grief over the loss of lives in the incident.
Additional deputy commissioner of Police (West) Umesh Ojha said the incident took place in Phase II of Basni Industrial Area.
"In the evening, between 5.30pm and 6pm, a wall of the factory suddenly collapsed. There was a loud sound and about 15 labourers were buried under the debris," he said.
During the rescue operation, the bodies of six labourers were pulled out from the rubble. Ten labourers, who were injured, were rushed to the hospital. They are undergoing treatment at Mathura Das Mathur Hospital and AIIMS, he said.
Ojha said none of the victims has been identified so far. Some of them are said to have come from other districts and working under a contractor.
"We would also look into the matter with regard to any negligence by the civil contractor and register a case against him accordingly," he said.
Administration and police officials are supervising the rescue operation. Lighting arrangements have been made to facilitate the operation at night.
In a tweet in Hindi, Gehlot said the news about the death of labourers was "extremely unfortunate".
The state government has announced an ex-gratia of Rs 2 lakh for the families of each of the deceased. The probe into the matter has been handed over to the divisional commissioner, Jodhpur.