Turkish F-16 fighter jets were scrambled after Russian warplanes infiltrated Turkey’s sovereign airspace over the weekend, according to a press release from Ankara's foreign ministry Monday. Russian officials talking to the BBC said that the stray aircraft, which entered into the country from Syria, had suffered a “navigational error” and the issue had been resolved with the Turkish government.

The incident, which took place Saturday, comes amid Russian airstrikes that began last week against anti-Syrian government rebels and the Islamic State militant group, also known as ISIS. Moscow has vowed to support Syrian President Bashar Assad’s authoritarian regime, despite pressure from the U.S. and Europe that Russian military interference could further destabilize the country and the Middle East region.

“The Acting Undersecretary of the Ministry summoned the Ambassador of the Russian Federation in Ankara to the Ministry and strongly protested this violation, demanded that any such violation not be repeated and affirmed that, otherwise, the Russian Federation will be responsible for any undesired incident that may occur,” said the Turkish foreign ministry press release.

The Turkish military, which is a member of NATO, also reported that an unidentified aircraft patrolling the skies between Turkey and Syria’s border harassed its jets Sunday. 

Turkish Prime Minister Ahmet Davutoglu said "the rules of engagement are clear," whoever violates its airspace, according to the BBC report, signaling that a repeat incident could result in military engagement between Moscow and Ankara. The U.K. ambassador to Turkey said on Twitter that the incursion was "reckless and worrying" and said NATO allies stood "shoulder to shoulder" with Turkey.

Meanwhile, Russia has continued it fierce bombing campaign inside Syria Monday, as Sukhoi Su-24M bombers allegedly hit ISIS communications infrastructure in the Syrian province of Homs, according to a Russian Defence Ministry spokesman Igor Konashenkov, who spoke with the Moscow-based news site Tass.

"The building that housed the communications center was destroyed as a result of a direct hit. The communications reconnaissance data have confirmed its destruction," he said.