(Trends Wide) — Russian pilots attempted “dogfights” (close dogfights) with US planes over Syria, according to a US Central Command spokesman, as part of a recent pattern of more aggressive behavior.

The attempts occurred in several of the most recent cases of aggressive behavior by Russian Pilots, Col. Joe Buccino said.

The Russian pilots do not appear to be trying to shoot down US planes, a US official told Trends Wide, but they may be trying to “provoke” the US and “lead us into an international incident.”

In military aviation, a “dogfight” (the literal translation is dogfight) is an air combat, often at relatively short distances.

A video released by the US Central Command on April 2 shows a Russian SU-35 Fighter Jet performing an “unsafe and unprofessional” intercept of a US F-16 fighter jet.

A second video from April 18 shows a Russian fighter violating coalition airspace coming within 600 meters of a US plane, a distance a fighter jet can cover in a matter of seconds.

In recent years, the US has used a détente line between the two militaries in Syria to avoid mistakes or inadvertent encounters that can inadvertently lead to escalation.

US officials have communicated with their Russian counterparts about the recent incidents, and the Russians have responded, the official said, but “never in a way that acknowledges the incident.”

Since the beginning of March, Russian planes have violated deconflict protocols a total of 85 times, the official said, including flying too close to coalition bases, missing the deconflict line and more.

That also includes 26 cases in which armed Russian planes flew over US and coalition positions in Syria.

“It seems to be consistent with a new way of operating,” the official said. The US pilots have refused to participate in dogfights and are adhering to the protocols of de-escalation measures, the official added.

The United States has approximately 900 service members in Syria as part of the ongoing campaign to defeat ISIS.

The most aggressive behavior by Russian pilots has also occurred outside of Syria.

In March, a Russian SU-27 fighter jet collided with a US MQ-9 Reaper drone in international airspace over the Black Sea.

The collision damaged the drone’s propeller and forced it to plunge into the water in an incident the US described as “unsafe, unprofessional” and even “reckless”.

“It is worrisome because it increases the risk of miscalculation, and given incidents such as the MQ-9 intercept and subsequent shootdown over the Black Sea, this is not the type of behavior you would expect from a professional Air Force,” said Lt. Gen. Alexus Grynkewich of the Air Force Central Command, in a statement earlier this month.

Subsequently, Russia presented state awards to the pilots of Russian aircraft.