Five people died on Thursday after a major fire broke out at Serum Institute of India plant in Pune’s Manjari area, ANI reported. The company has been engaged in large-scale manufacturing of the coronavirus vaccine, Covishield, developed by Oxford University and pharmaceutical firm AstraZeneca.

“Four people were evacuated from the building but when it came under control, five bodies were found by our jawans,” Pune Mayor Murlidhar Mohol said. “The five people who died, were perhaps the workers at the under-construction building.”

Serum Institute chief Adar Poonawalla said he is “deeply saddened” by the news. “We have just received some distressing updates; upon further investigation we have learnt that there has unfortunately been some loss of life at the incident,” he tweeted. “We are deeply saddened and offer our deepest condolences to the family members of the departed.”

The blaze began at an under construction building inside Terminal 1 gate of the Serum Institute. Maharashtra Health Minister Rajesh Tope said the fire started due to welding work. “Insulation material, which is inflammable, was kept near the work site,” he said.

Earlier, Maharashtra Chief Minister Uddhav Thackeray said that six people were evacuated from inside the building. “Prima facie it seems that the fire was caused by an electric fault,” he added. “The Covid vaccine is safe. I have not spoken to [Serum Institute chief] Adar Poonawalla till now.”

The Maharashtra government has ordered an inquiry into the incident, according to News18. “CM Uddhav Balasaheb Thackeray is in touch with the Pune Municipal Commissioner and is taking complete on-ground updates,” his office tweeted. “He has directed the state machinery to coordinate and ensure that the situation is under control.”

Deputy Commissioner of Police Namrata Patil told PTI that the fire broke out at 2.45 pm on the fourth and fifth floor of the SEZ 3 building on the Serum Institute premises. Ten fire and two water tenders were sent to the spot, Mohol told the Hindustan Times. Fire erupted once again after 7 pm and operations were underway to douse it, ANI reported.

Poonawalla said the incident will not affect the production of the coronavirus vaccine. He told NDTV that they were yet to calculate the losses incurred. “We’ll assess damage later,” he added.

Serum Institute officials had also said that the blaze would not affect the production of Covishield vaccine. According to Serum Institute Executive Director Suresh Jadhav, the fire was reported at the facility where BCG tuberculosis vaccine-related work was going on. The facility where Covishield vaccine is being manufactured and stored is far away from this facility, Jadhav told the Hindustan Times.

“This plant has nothing to do with Covishield,” said SII official Vivek Pradhan. “The Covishield plant is at least a km away from this building. Only raw material was inside this building. Nobody is trapped there. There were not more than 5-6 people in that space.”

India started its coronavirus vaccination drive on January 16. Two vaccines – Serum Institute’s Covishield and Bharat Biotech’s Covaxin – are being administered to frontline health workers across the country.