At least 17 people were killed in an explosion on Thursday at a pharmaceuticals manufacturing plant in southern India’s Andhra Pradesh state, a district government official said.

The fire broke out in the afternoon at privately held Escientia Advanced Sciences’ 40-acre manufacturing unit that was operational since 2019 in the state’s Anakapalli district, according to district collector Vijaya Krishnan.

“The injured have been shifted to nearby hospitals...it appears that there could have been a blast at the chemical reactor,” Krishnan’s office told Reuters, adding that the blast occurred during lunchtime at the unit.

Nearly 40 people were injured and rescue operations had been completed, the official, Industries Secretary N. Yuvaraj, told Reuters.

Escientia did not immediately respond to a request for comment. The state government has ordered an inquiry into the incident.

Officials said they were scanning closed-circuit television footage and questioning the injured to decide if human error was responsible for the blast.

“Preliminary investigation shows ... there was some vapour leak that led to chemical reactions, which caused the explosion,” added Yuvaraj, who identified the solvent involved as methyl tert-butyl ether.

In a post on X, Prime Minister Narendra Modi offered condolences to the relatives of the dead.

India, known as the pharmacy of the world, is home to many plants that make pharmaceuticals.

Last year, two people were killed and five others were injured in a similar fire accident that broke out in a solvent reactor at a unit of Sahithi Pharma in the Anakapalli district.