MOSCOW — Two Russian airmen died in Syria after their helicopter was shot down by fighters of the Islamic State, Russia’s military said on Saturday.

The episode occurred on Friday east of the ancient city of Palmyra, according to a Defense Ministry statement reported by Tass, the state-run news agency.

The Islamic State claimed responsibility for the attack, according to the SITE Intelligence Group, which monitors jihadist websites.

The two Russians were making a test flight in the Homs region with a Syrian Mi-25 helicopter that was carrying ammunition, the Defense Ministry said. It said Islamic State fighters broke through the lines of the Syrian government forces east of Palmyra at the same time.