India, April 22 -- A four-member team constituted by India's oil ministry is in Rajasthan to investigate a fire at a refinery, even as HPCL said the incident is not expected to have a material financial or operational impact, and that all units are structurally safe with no effect on other sections.

The fire broke out on April 20 at the refinery of HPCL Rajasthan Refinery Limited, a day before it was to be inaugurated by Prime Minister Narendra Modi. The fire in the crude distillation unit - the main unit of a refinery - was likely caused by a hydrocarbon leak from a valve or flange in a heat exchanger circuit, Hindustan Petroleum Corporation Ltd (HPCL) said.

The blaze was confined to the heat exchanger stack and was quickly brought und...