The toll from the pharma plant explosion in this district on Monday rose to 12 , Telangana Minister Damodara Raja Narasimha said.
At least 34 persons were injured in the explosion, triggered by a suspected chemical reaction, the health minister said.
"As many as 12 people died and 34 people are under treatment. We are hopeful that there would be no more (deaths)," the minister told reporters.
Labour Minister G Vivek Venkatswamy said: "Eight people died in the morning. Now, four bodies were found." Both the ministers visited the site.
The explosion took place at a reactor in the plant of Sigachi pharma company in the Pashamylaram industrial estate due to the suspected chemical reaction where fire also broke out.
Earlier, Inspector General of Police (Multizone) V Satyanarayana, quoting factory sources, said there were 150 people in the factory at the time of the blast. Ninety persons were in the same area where the explosion occurred.
He said the explosion occurred between 9.28 am and 9.35 am. The management immediately reached out to the local police who in turn alerted the fire department.
About ten fire fighting engines were pressed into service, he further said, adding the personnel of NDRF and SDRF were also engaged in the rescue operation.
The fire was brought under control, he added.
Asked how many workers were working at the time of the tragedy, he said effort was on to ascertain the exact figure as the person who maintains record of the workers' details is believed to have died.
PM Modi expressed grief over the fire tragedy and conveyed condolences to those who lost their loved ones in the incident. He wished an early recovery to the injured.
In a post on 'X', he announced an ex-gratia of Rs 2 lakh from the Prime Minister's National Relief Fund for the next of kin of the deceased and Rs 50,000 for the injured.
Chief Minister A Revanth Reddy expressed anguish over the incident and directed officials to take all steps to save the trapped workers and provide them advanced medical care, an official release said.
Sigachi Industries Limited is a pharmaceutical company dedicated to pioneering advancements in Active Pharmaceutical Ingredients (APIs), Intermediates, Excipients, vitamin-mineral blends, and Operations and Management (O&M) services, according to the company's website.
There was no immediate reaction from the company.