As many as seven persons were killed and more than 40 injured following an explosion at a chemical factory in Maharashtra's Thane district on Thursday afternoon, officials said.

As a boiler exploded at Amudan Chemicals located in Phase 2 of Dombivli MIDC area around 1.40 pm, the impact of the explosion and the resultant blaze affected adjacent factories.

As per the preliminary information, those killed were working in neighbouring factories, said Maharashtra industries minister Uday Samant.

Five men and two women were killed in the incident but their bodies were charred beyond recognition, said Yasin Tadvi, chief of the disaster management cell of the Thane Municipal Corporation.

"My deepest condolences to the families who lost their loved ones," said deputy Chief Minister Devendra Fadnavis on X.

"Injured are being treated at AIMS, Neptune and Global hospitals, and every kind of assistance is being provided. Praying for their speedy recovery. Various teams and administrative officials are on the spot for rescue operations," he added.

Besides fire brigade, police and local officials, the NDRF too was taking part in the rescue operation, officials said.

Minister Samant told PTI that the plant where the explosion took place was not in operation for the last few months and had restarted only a few days ago.

Samant, local MP Shrikant Shinde and MLA Raju Patil visited the site inside the Maharashtra Industrial Development Corporation (MIDC) area, some 40 km from Mumbai.

The blast was so loud that it was heard a kilometre away, an eyewitness said. Glass windows of adjoining buildings cracked while many houses in the vicinity were damaged, officials said.

Thick clouds of smoke could be seen hovering over the factory.

Speaking to reporters at Chhatrapati Sambhajinagar, Chief Minister Eknath Shinde said a massive rescue and relief operation was underway at the site and he had directed the district collector to conduct a detailed inquiry into the incident.

Plans were afoot to shift hazardous chemical factories from Dombivli to Ambernath MIDC in the district, the CM said in reply to a question.

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