The Russian military says its jets in Syria have flown their first joint combat mission with the Syrian air force.

The Defense Ministry said that a pair of Syrian MiG-29 fighter jets escorted two Russian Su-25 ground attack aircraft during Thursday's mission.

The ministry said that Syrian pilots had previously visited the Russian base to discuss details of the mission. It released a video showing the Russian planes taking off from Hemeimeem air base and being joined in flight by the Syrian jets.

Russia has conducted an air campaign in Syria since Sept. 30. Moscow insisted that Russian warplanes were focusing their strikes on the Islamic State group and other extremists, but the U.S. and its allies said they also hit moderate groups fighting Syrian President Bashar Assad's army.