A reactor in block-A of the factory caught fire and exploded at around 6 am today, police said. Some 30 workers were on the premises at the time.
Police Inspector, Elamanchili, H Malleswara Rao said V Ramu (36) of Narsipatnam and G Subba Rao(31) of Alamuru in East Godavari district, both working as chemists, died on the way to the hospital.
Fire tenders from Tuni in East Godavari district and Payakaraopeta were pressed into service to douse the fire.
A group of workers and trade union leaders staged a sit-in outside the factory premises, alleging failure by the management to adopt safety measures.
District unit of CPI(M) demanded a compensation of Rs 30 lakh for the kin of the each dead worker and Rs 10 lakh for every injured worker.