The Press Trust of India news agency said two officers were among the 20 soldiers to have died in the blaze at the depot in Pulgaon, near the city of Nagpur in the state of Maharashtra.
The NDTV network also reported that 20 people had been killed in the huge blaze which it said had broken out after an explosion at the depot in the early hours of the morning.
Thousands of families living in the area had been evacuated from nearby towns and villages.
