Nato fighter aircraft conducting the Baltic Air Policing mission were scrambled four times from 10 to 16 December after Russian military aircraft flew near international airspace over the Baltic Sea.
A TU-134 was intercepted by Nato aircraft on 10 December whilst flying from Kaliningrad to mainland Russia without the flight plan.
It maintained radio contact with the regional air traffic control centre without using its on-board transponder.
A Nato fighter jet also identified and escorted an AN-26 on 13 December.
The AN-26 was not using its on-board transponder and flying without the flight plan from mainland Russia to Kaliningrad.
On 14 December, Nato aircraft were again scrambled to intercept another AN-26 with a switched-off on-board transponder.
The Nato air policing peacetime collective defence mission is aimed at protecting the Nato Alliance Member’s airspace and is carried out under the Nato Integrated Air and Missile Defence System (NATINAMDS).
Aircraft are scrambled to respond to military and civilian aircraft in distress or those that do not follow international flight regulations and approach Allies’ airspace.
Russian has been posing military challenges in recent years by continually entering international airspace unlawfully.
Nato jets intercepted one SU-27 and an SU-30 on 15 December. The fighter jets were flying without the flight plan from Kaliningrad to mainland Russia and were not using the on-board transponder and maintaining the radio communication.