Rae Bareli District Magistrate Sanjay Kumar Khatri told the number of injured in the Wednesday's National Thermal Power Corporation (NTPC)plant blast was 64.

Ten persons injured in the state-run power plant blast that occurred around 3.30 p.m. have been relieved after medical aid.

The massive explosion took place in the 500 MW boiler unit in Unchahar.

The NTPC was also probing the incident which took place due to "access ash deposition" in a furnace.

Many were feared trapped on Wednesday when the fire broke out inside the boiler and a huge ball of dust rose after the explosion. It made rescue operations difficult, an official told.

Contractual labourers raised slogans on Thursday against the NTPC management.

They claimed they had forewarned about the "impending" disaster at the unit-six as the temperature near the furnace was steadily rising.

Angry locals and family members of the injured have claimed that there was complete absence of medical facilities at the NTPC campus, which led to the spike in the number of casualties.

Congress Vice President Rahul Gandhi and his sister Priyanka Vadra are scheduled to visit Rae Bareli, the Lok Sabha constituency of their mother and party President Sonia Gandhi, later on Thursday.

Union Minister R.K. Singh and state Power Minister Shrikant Sharma are also slated to visit.