Four army jawans were killed in a blast at a firing range in Pokhran in Rajasthan.
The incident occurred last night when the troops were firing 81 mm mortars and one of the shells exploded, killing the four jawans at the range, about 40 km from here, Army sources said on Monday.
The army has ordered a probe into the reasons behind the accident, they said in New Delhi.
In March 2008, three army personnel were killed and two others were injured during the 'Brazen Chariots' exercise in the same field firing range.
A 125-mm mortar gun had exploded even as the personnel were firing it for a live demonstration while the Army's top brass, defence attaches and diplomats from foreign countries were watching the exercise.