Fifteen labourers suffered burn injuries at the Birla cement factory in Rajasthan's Chittorgarh district, an official said here on Monday.
The incident took place on Sunday evening when burning coal fell on them at the factory falling under the Chanderia police station.
The injured were were rushed to a government hospital in Udaipur.
Owing to critical injuries, doctors referred 14 of the labourers to Ahmedabad for treatment, Additional District Collector Mukesh Kalal said.
He said the matter was being investigated and a report would be prepared after verifying the security measures available at the factory.
Police said a case had been registered against the factory management under Sections 287, 336, 337 and 308 of the IPC.