"At approximately 12:15 p.m. Moscow time [09:15 GMT] in the Sunzhensky region ... an armed group of unidentified individuals fired upon Russian military personnel on a reconnaissance and search mission," said the spokesman for the Investigations Committee of the Prosecutor General's Office for Ingushetia.
The spokesman said that Roman Bernikov, 20, was killed in the attack and Soslan Tedeyev, 23, and Yaroslav Novikov, 19, suffered gunshot wounds.
"When fire was returned, one of the militants was shot dead and the rest escaped. The identity of the dead militant is being established," he said.
He added that investigations were continuing into the incident.