Turkish jets have shot down an unidentified drone that had violated the country's airspace at the border with Syria, the military said.
The drone was shot down after it ignored three warnings for it to leave, the military said, adding that it was not immediately known which country the aircraft belonged to. It crashed inside Turkish territory.
Earlier this month, Turkey complained about Russian warplanes violating its airspace, intrusions that also drew strong condemnation from Turkey's Nato allies.
The United States, Russia and the Syrian government all operate drones in the region.
Igor Konashenkov, a spokesman for the Russian defence ministry, told Russian news agencies that all Russian jets have safely returned to their base and all Russian drones "are functioning normally".
The Lebanon-based pro-Syrian Al-Mayadeen TV quoted an unnamed Syrian military official as saying that no Syrian or Russian warplane or drone was shot down over Turkey. The official added that Syrian or Russian warplanes or drones did not violate Turkey's airspace.
Since 2013, Turkey has shot down a Syrian military jet, a helicopter and an unmanned surveillance drone that have strayed into Turkish airspace. The incidents occurred after it changed its rules of engagement following the downing of a Turkish fighter jet by Syria.
Turkey has also reported numerous incidents of harassment of its F-16 jets patrolling the Syrian border by Syrian fighter planes or Syria-based surface-to-air missile systems locking radar on them.
To ease tensions with Russia, a high-level Russian delegation led by the country's deputy air force commander held talks on Thursday with Turkish military officials in Ankara.
The military said the sides had discussed measures Russia was taking to avoid further incidents.
Turkish foreign minister Feridun Sinirlioglu said the drone crashed about two miles inside Turkish territory.
He said: "We have not been able to establish who the drone belongs to, but we are able to work on it because it fell inside Turkish territory."
Russia strongly denied ownership of the drone.
"I state with absolute responsibility that all our drones are either performing tasks or staying at the base," said Colonel-General Andrei Kartapolov, of the Russian military's general staff, at a meeting with foreign military attaches in Moscow.