Nine airmen were killed when two Russian-designed military helicopters crashed on Thursday after taking off in the western Indian state of Gujarat, police said.
Indian media said the two helicopters collided in mid-air after taking off on a training mission from a nearby military base but authorities said they could not confirm the reports.
Three other soldiers were injured in the accident involving the two Mi-17 helicopters, which form the mainstay of the rotorwing fleet of the Indian Air Force.
"The two helicopters carrying nine soldiers and officers crashed in a cotton plantation" in Jamnagar district, local police chief Harikrishna Patil told AFP by telephone from the site of the accident.
He said nine men on board the two aircraft were killed, and three others injured in the accident have been hospitalised.
"One of the aircraft immediately caught fire after crashing and while the other is totally destroyed -- it did not catch fire," Patil said.
He added rescue workers were seeking to extract a soldier from the wreckage but declined to confirm media reports of a collision.
In New Delhi, air force spokesman Wing Commander Gerard Galway confirmed the twin crashes in Jamnagar, but said he could not immediately provide further details.
India plans to buy up to 400 helicopters worth hundreds of millions of dollars to replace its ageing fleet of Russian- and British-supplied rotorcraft.