AT LEAST 39 people have died after a chemical reactor exploded inside a drug factory in India.

Dozens are still missing after the horror blast sparked an inferno at the building and left workers trapped inside.

The chemical factory, used by Sigachi Industries, sat in the Pashamylaram industrial estate in Telangana’s Sangareddy district.

Police in Telangana said more than 140 people were working in the plant at the time of the blast with more than 60 directly impacted.

Seventeen workers are still unaccounted for as officials fear they may be trapped under the charred debris.

A massive rescue team was deployed to extinguish the flames and try to move the rubble with excavators seen at the factory this morning.

GV Narayana Rao, director of the fire response team, confirmed the factory had completely collapsed due to the explosion.

“We are currently in the process of clearing the debris,” he explained. “Once we have completed this task, we will then be able to determine whether there are any bodies still buried beneath or if the area is completely clear.”

Terrified plant worker Chandan Gound, 32, added: “I came out [of the plant] to use the restroom and heard a loud blast.

“It sounded like a bomb blast. I came out and saw fire. A part of the fire also spread towards me. I jumped the wall and escaped.

“Many of them [working inside] managed to escape, but a large number were trapped and could not come out.”

Investigations are still ongoing into what caused the explosion.

Telangana Chief Minister A Revanth Reddy has now told officials across the state to conduct thorough inspections into all chemical companies.