At the end of the week, air-policing jets identified and accompanied two Russian fighter-jets Su-27 flying in the international airspace. The NATO jets were scrambled two more times on Friday over An-12 transport airplane.
All four Russian aircraft had their onboard transponders off.
The NATO air-policing mission is conducted from Lithuania and Estonia. In response to the upcoming Russian-Belarusian exercise Zapad 2017, it was reinforced with additional US fighter-jets at the end of August.