Turkey’s heads of state have made abundantly clear they will react with force to another Russian incursion into their airspace after two incidents over the weekend, though Turkish forces did not respond with violence to a third reported incident with an unidentified jet.

“Even if it’s a flying bird, whoever violates Turkish airspace will be subject to the necessary actions,” Turkish Prime Minister Ahmet Davutoğlu told a Turkish television outlet on Monday. “Turkey’s rules of engagement are valid for Syria’s, Russia’s or another country’s warplanes.”

Turkish President Recep Tayyip Erdoğan made a similar remark on Tuesday, calling the positive relations between Turkey and Russia “obvious,” but adding, “They would lose us” if they continue violating Turkish airspace. “If Russia loses Turkey, it would lose a lot.” He warned that “it is not suitable for Turkey to accept” Russia’s behavior, and that, beyond the Turkish government, “NATO has issued a stern ultimatum.”

In addition to public statements, the Turkish Foreign Ministry summoned the Russian ambassador to Ankara to protest, and Foreign Minister Feridun Sinirlioğlu called Russian Foreign Minister Sergei Lavrov personally to warn him to ensure further violations of Turkish sovereignty do not occur.

NATO has responded to the matter with a statement condemning Russia’s actions and noting that they do not believe the incursions were accidental. Calling the transgression “unacceptable,” NATO Secretary General Jens Stoltenberg said in a statement, “Intelligence that we have received provides me with reason to say it doesn’t look like an accident.” The Russian government blamed “unfavorable weather conditions” for the “navigation error” and warned observers not to chase “conspiracy theories.” Responding to Stoltenberg’s statement on Tuesday, Russian NATO envoy Alexander Grushko accused “the West” of trying to tarnish Russia’s image. “The impression is that the incident in Turkish airspace was used to plug NATO as an organization into the information campaign waged by the West to distort the aims of the operations carried out by the Russian air force in Syria,” he told reporters.

On Saturday, a Russian warplane engaging in combat in Syria entered as deep as five miles into Turkey. The next day, an unidentified fighter jet harassed two Turkish F-16s doing patrols near the Turkish border, in the “ISIS-free zone” that Turkey and the United States had attempted to establish in Syria. This prompted the stern warnings from Turkey.

Turkish newspaper Hurriyet is reporting, however, that a third incident occurred on Monday, following the public statements from Turkey and NATO. “Eight Turkish F-16 fighter jets were harassed by unidentified MIG-29 aircraft for four minutes and 30 seconds during a patrol flight on the border with Syria on Oct. 5,” the newspaper reports. The Turkish military made the incident public on Tuesday. Zaman, another Turkish outlet, specifies the type of harassment endured by the Turkish planes: “a MIG-29, whose nationality could not be identified, for 4 minutes and 30 seconds [put] them under radar lock.”

The Turkish government has yet to elaborate on its public statements in light of the third incident. The Russian government has also not spoken since its initial statements in unrelated news: government-owned fuel Gazprom announced Tuesday it would significantly reduce the capacity of a pipeline project it has been developing in Turkey, which would allow it to ship gas across the continent without having to enter Ukraine.