More than 20 survivors were battling for their lives with severe burns following the blast in a newly-operated unit at the 1,550-megawatt plant run by state-owned NTPC, officials said. More than 80 others suffered injuries in the explosion.

Rahul Gandhi visited the NTPC plant in Uttar Pradesh's Raebareli on Thursday.
"A magisterial inquiry has been initiated. This two-member technical team will submit findings within seven days," Mr Khatri said.
In a statement, the NHRC said an investigation was needed to ascertain whether negligence or errors had caused the explosion, and asked the state government to submit a detailed report within six weeks.

The boiler pipe burst in a 500 MW power unit in the NTPC plant that started operating in March.
The power ministry and state government have both offered cash compensation to the families of the deceased and to the injured. Union Power Minister RK Singh visited the site and at one point even came face to face with Rahul Gandhi, who took a break from campaigning in Gujarat to fly to meet the victims and their families.
The Raebareli Lok Sabha seat is represented by his mother, Congress president Sonia Gandhi. Mr Gandhi joined other leaders of the opposition in demanding a judicial inquiry, suggesting that facts could be concealed.
(With inputs from Reuters and PTI)