Chandigarh | Five people were killed and nearly 30 others injured in a blast in a firecracker manufacturing and packaging unit near a village in Lambi in Punjab's Sri Muktsar Sahib district, police said on Friday.

Police said the incident occurred around 1 am.

The blast took place in the two-storey factory unit located on Singhewala-Kotli road in Sri Muktsar Sahib on the Punjab-Haryana border, Lambi's Deputy Superintendent of Police (DSP), Jaspal Singh, said over the phone, adding that migrant labourers worked at the unit.

The injured were taken to hospitals, including AIIMS Bathinda, and most of them were stated to be out of danger, the DSP said, and added that the cause behind the blast is under investigation.

Senior Superintendent of Police, Sri Muktsar Sahib, Dr Akhil Chaudhary said the blast occurred in one of the rooms in the manufacturing setup of the unit, leading to collapse of the roof and other parts of the building.

Many were trapped under the debris and rescue operations were launched as soon as the police received information about the incident, the SSP said.

It seems that the blast was caused by materials used in the manufacturing of firecrackers, though the exact cause can be ascertained after investigations and forensic examinations, the SSP said over the phone.

DSP Jaspal said 40-50 workers, including many of those who were sleeping on the premises, were present in the unit at the time of the incident.

Asked whether the firecracker manufacturing unit had necessary permissions required for it to operate, the SSP said records in this regard were being verified by the department concerned.