Turkish warplanes shot down a drone in Turkish air space near the Syrian border on Friday and its nationality has not yet been identified, a senior government official told Reuters.
The military said earlier in a statement that it had shot down an unidentified aircraft after it continued on its trajectory despite three warnings, in line with the NATO member's rules of engagement.
A U.S. official told Reuters that the U.S. suspects the aircraft brought down was a Russian drone, but Agence-France Presse reported that Russian officials say all of its planes in Syria are safe and that its drone are "working as normal."
"All the Russian planes in Syria have returned to the Hmeimim air base after completing their tasks. Russian unmanned aerial vehicles monitoring the situation on the territory of Syria and carrying out air reconnaissance are working as normal," defence ministry spokesman Igor Konashenkov told Russian news agencies.
Broadcaster NTV said the drone was brought down around 1.9 miles inside Turkish air space.
Two Russian jets violated Turkish air space earlier this month, bringing the Syrian conflict across NATO's borders, and Turkey has warned it would respond if the violations continued.
The Russian air force officially informed the Turkish military on Thursday about the violations and about steps it would take to prevent a repetition.
Turkey has also reported unidentified aircraft and Syria-based missile air defense systems harassing its warplanes.
Al Jazeera and wire services