The victims, all relatives, belonged to Anantapuramu district and were on their way to Tirupati from Dharmavaram to attend a wedding engagement ceremony scheduled for Sunday morning.
More than 50 workers were at work in the night shift when the mishap occurred in unit-4.
While the ruling party blamed unnamed forces behind the arson, all opposition parties hit out at the Jagan Mohan Reddy government over its "gross failure" in controlling the situation.
Buoyed by the recent victories in bypolls, Rahul was keen to revamp the state unit.
Congress legislators from the coastal Andhra and Rayalaseeema would soon undertake a 48-hour hunger strike in Hyderabad in support of united Andhra Pradesh.
Andhra Pradesh Civil Supplies Minister D Sridhar Babu resigned from the Cabinet on Thursday night protesting the divesting of legislative affairs portfolio that he had been holding for over three years now.
Even as the Union Cabinet on Thursday took up the note on Telangana state for discussion, the Seemandhra leaders fighting to keep the state united, met Andhra Pradesh Chief Minister N Kiran Kumar Reddy to discuss their counter strategy.
President Pranab Mukherjee, PM Narendra Modi, Congress leader Sonia Gandhi and Left parties, among others, condoled the demise of former Cuban president.
