BENGALURU, Dec 21 (Reuters) - A fire at Indian Oil Corp"s (IOC.NS) Haldia refinery killed three people and injured 44, the company said on Tuesday. The incident occurred at around 2:50 p.m. local time (0920 GMT) during maintenance-related work at a gasoline making unit of the 160,000 barrel-per-day (bpd) refinery, the company said. IOC, the country"s top refiner, has shut the coastal refinery in eastern India, in the first week of this month for about 50 days for maintenance, a company spokesman said. "The primary cause seems to be a flash fire leading to burn injuries to 44 persons and 3 persons have unfortunately succumbed to their injuries," it said in a statement. The fire was immediately extinguished and the situation is under control, the company said, adding that authorities were investigating the cause of the incident.