The fire broke out around 12.05 p.m. in one of the rooms of the Modular Laboratory where the two students were working.
"The bodies (of the victims) have been charred beyond recognition and were discovered by the firemen on entering the laboratory after extinguishing the fire," a spokesman for BARC said here.
Police sources said that the fire may have erupted following a suspected chemical reaction that led to a blast in the laboratory housing analytical instruments.
However, there was no danger to the main reactor in the BARC or any other sensitive facilities that could lead to radiation or radioactivity, the spokesman said.
Three fire tenders rushed to the spot and the blaze was brought under control within an hour.
According to reports, the victims were identified as Umang Singh of Mumbai and Partha Bagga of Kolkata, but BARC officials were not willing to comment.
The laboratory usually houses over 60 research students and assistants of whom only two were present at the time of the incident.
It is not known whether there was a laboratory supervisor on the premises when the incident took place.
The BARC authorities and the Mumbai Police have launched simultaneous investigations into the incident, said to be the first of its kind in the complex.
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