Search and rescue operations are underway as some more labourers are feared trapped under the debris, police said.
"Late last evening, the roof of an under-construction building collapsed in Phase II of Basni industrial area. Eight people were killed and several others were injured -- some of them critically," a police official said, reports Xinhua.
The incident took place between 5 to 6pm when the workers were working at the site.
Rajasthan Chief Minister Ashok Gehlot expressed grief over the loss of lives and described the death of labourers as "extremely unfortunate".
Reports said over 16 labourers were present in the building at the time of the accident. The injured have been sent to hospitals.
It was not immediately known what caused the roof to collapse.
Additional Deputy Commissioner of Police (West) Umesh Ojha said there was a loud sound and about 15 labourers were buried under the debris.
During the rescue operation, the bodies of six labourers were pulled out from the rubble while the 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 yet. Some of them are said to have come from other districts and are working under a contractor.
"We’d also look into the matter with regard to any negligence by the civil contractor and register a case against him accordingly," he said.
Meanwhile, the state government has announced compensation of Rs2 lakh for the families of each of the victims.
Investigation into the matter has been handed over to the divisional commissioner, Jodhpur.
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