A major fire broke out in two mother plants of the public sector Numaligarh Refinery Ltd (NRL) in upper Assam's Golaghat district on Friday morning.
No casualty or injury has been reported.
The fire broke out in the crude distillation unit (CDU) and vacuum distillation unit (VDU) of the refinery at around 5.25am and the blaze was contained within an hour, a spokesperson of the refinery said.
Four fire tenders from the refinery and three others from the district administration battled the blaze which was doused at 9.46am when the NRL authority declared "all clear", she said.
The two plants have been shut down and the other units of the refinery will be shut down in a phased manner as a precautionary measure, she said.
A high-level committee has been set up to assess the damages and cause of the fire, the spokesperson said.
NRL was set up in 1992 as part of a proposal for a refinery in the Assam Accord signed between All Assam Students Union (AASU) and the Central government on August 15, 1985 signalling an end to the 6-year-long Assam agitation.