A Russian officer walks next to drones that allegedly attacked a Russian air base in Syria and were captured by the Russian military. They were displayed at a briefing in the Russian Defence Ministry in Moscow, Russia, on Jan. 11, 2018. (Pavel Golovkin/AP)
Just weeks after Russian President Vladimir Putin declared victory in Syria, Russian military outposts in the country have come under rebel attacks that are challenging Moscow's gains. (Russian Defence Ministry Press Service via AP)
One of the drones that was forced to land after an unsuccessful attack attempt sits at a table at Hemeimeem air base in Syria. Russia's Defence Ministry said its forces repelled a series of drone attacks on the air base and a naval facility in Tartus (Russian Defence Ministry Press Service via AP)
Russia's Defence Ministry spokesman Igor Konashenkov, left, and Maj. Gen. Alexander Novikov, head of the Russian General Staff's department for the development of UAVs, attend a briefing on recent drone attacks on Russia's bases in Syria, in the Russian Defence Ministry headquarters in Moscow on Jan. 11, 2018. (Kirill Kudryavtsev/AFP via Getty Images)
Mortar shells are lined up next to one of the drones that was forced to land after an unsuccessful attack attempt at Hemeimeem air base in Syria. (Russian Defence Ministry Press Service via AP)
Russia's Defence Ministry spokesman Igor Konashenkov, left, and Maj. Gen. Alexander Novikov, head of the Russian General Staff's department for the development of UAVs, attend a briefing on recent drone attacks on Russia's bases in Syria, in the Russian Defence Ministry headquarters in Moscow on Jan. 11, 2018. (Kirill Kudryavtsev/AFP via Getty Images)
A Russian officer stands next to drones that attacked the Russian air base in Syria and were captured by the Russian military are displayed at a briefing in the Russian Defense Ministry in Moscow, Russia, Thursday, Jan. 11, 2018. Saturday's, Jan.6, 2018 raid against the Hemeimeem air base and a Russian naval facility in Tartus involved 13 drones, seven of the drones were shot down by air defense systems and the remaining six were forced to land, according to the Russian Defense Ministry. (AP Photo/Pavel Golovkin)
One of the drones that allegedly attacked a Russian air base in Syria and was captured by the Russian military is displayed at a briefing in the Russian Defense Ministry in Moscow, Russia. (Pavel Golovkin/AP)
A reported Jan. 6, 2018, raid against the Hemeimeem air base and a Russian naval facility in Tartus involved 13 drones, seven of which were shot down by air defense systems and the remaining six were forced to land, according to the Russian Defense Ministry. (Pavel Golovkin/AP)