The Turkish military says it has shot down an unidentified drone aircraft in Turkish airspace near the Syrian border.
In a written statement on October 16, the military said the unidentified aircraft did not respond to three warnings and so was shot down in accordance with Turkish military rules of engagement.
A senior official in Turkey's government confirmed in an interview with the Reuters news agency that the aircraft was a drone.
Turkish authorities said they have sent investigators to the crash site in Turkish territory to try to identify who was operating the drone.
Russia, Syria's armed forces, and the United States all use drone aircraft in the region.
The Russian state news agency RIA Novosti quoted a Russian military source as saying all its aircraft in Syria were "operating as planned."
CNN Turk reported that the aircraft was shot down near the Turkish town of Kilis, about 3 kilometers from the Syrian border and some 90 kilometers north of the Syrian city of Aleppo.
NATO member Turkey has repeatedly complained that Russian aircraft carrying out air strikes in Syria have violated Turkish airspace.
A spokesman for Turkey's ruling Justice and Development Party said on October 7 that Ankara views incursions into its airspace by Russia "as a threat."