Raebareli: At least 20 people were killed and more than 100 wounded as a boiler exploded on November 1 afternoon in a power generating unit in Raebareli in Uttar Pradesh state.

The unit belongs to the National Thermal Power Corporation (NTPC), a government-controled plant.

The number of dead and injured may rise as many are believed to be trapped inside the unit. Many of the injured have suffered severe burns.

While NTPC has set up an inquiry to investigate the reasons for the accident, ADG (Lucknow zone) Abhay Prasad said that a case of negligence could be filed after rescue operation ends.

According to reports, a large number of NTPC workers, apart from some senior officials and engineers, were working at a 500 MW power unit when the boiler pipe exploded. The unit was installed in March at the 1,550 MW NTPC plant and functioning normally.

The blast was reportedly triggered in the duct connected to the boiler which is used for transferring ash of burnt coal. It is believed that the ash pipe got choked, leading to the blast. A massive fire broke out and a huge ball of dust rose after the explosion, making rescue difficult.

The plant in Unchahar is nearly 30 years old.

An NTPC statement said the workers heard a sudden abnormal sound before hot flue gases and steam escaped through an opening affecting people working around the area.

The plant has now been shut down. A National Disaster Response Force (NDRF) team has also been sent to help in the rescue effort.

The injured are being treated at two hospitals, including one in the NTPC campus. Those with the worst burn injuries are being taken to hospitals in Lucknow, around 110 km away.

The Unchahar plant started generating power in 1988 with five units of 210 MW each. The sixth unit was commissioned this year.

Prime Minister Narendra Modi tweeted to say that officials are ensuring that normalcy is restored. “Deeply pained by the accident at the NTPC plant in Raebareli. My thoughts are with the bereaved families. May the injured recover quickly. The situation is being closely monitored and officials are ensuring normalcy is restored,” he tweeted.

Chief Minister Yogi Adityanath, who is in Mauritius on a three-day official visit, has ordered 200,000 rupees for the families of the dead and 50,000 rupees for the badly injured.

Congress vice president Rahul Gandhi, who is campaigning in Gujarat for next month’s elections, said he will tomorrow visit Raebareli, which is the parliamentary constituency of his mother and Congress President Sonia Gandhi.

“Due to the unfortunate NTPC accident, I will visit Rae Bareli tomorrow morning. Will join Gujarat Navsarjan Yatra in the afternoon,” he tweeted.

“As of now, the immediate priority for us is to rush those injured to the best possible treatment and that is being done. All possible resources are being mobilized,” said Anand Kumar, one of the senior most police officers in the state.