A major blast set on fire the hydro-cracker unit of Numaligarh refinery in Assam on Saturday. Sources in Guwahati told Business Line that the Paresh Barua faction of ULFA has claimed responsibility.

The blast occurred at 6.40 p.m. and till 9 p.m. the fire could be brought under control. The Home Ministry had issued an alert for April 7, ULFA's foundation day.

Despite the State Government's additional security arrangements, the blast could not be thwarted, sources said.

PTI reports : According to a senior NRL official, there was no casualty or injury as the plant was automated and there was minimum deployment of human resources in the area.

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