According to the RAF's official social media page, the four planes, Eurofighter Typhoon multi-role, twin-engine fighter jets, arrived towards the end of April, from XI(F) Squadron, based at RAF Coningsby in Lincolnshire, England, with the official handover ceremony taking place Thursday.

The outgoing Luftwaffe planes were also Typhoons.

NATO Baltic air policing duties operate from two bases; in addition to Ämari, the base at Šiauliai, Lithuania, is also utlilized for the role.

Planes from the latter base are frequently scrambled in interception and escort duties, responding to military flights from the Russian Federation in international airspace over the Baltic Sea, close to the Lithuanian coast, often without pre-filed flight plans or functioning transponders on the required frequency. Such flights usually involve planes flying to or from the Kaliningrad exclave, a part of the Russian Federation cut off from the rest of the country and bordering two EU and NATO states, Poland and Lithuania.

Thursday also saw Hungarian and Spanish jets officially replace Polish planes, at Šiauliai, BNS reports, citing the Lithunian defense ministry. Hungary, which is leading the NATO air policing role, has deployed four Swedish-manufactured Saab JAS 39 Gripen single-engine multi-role fighters, from the Magyar Légierő, that country's air force. The Spanish Ejército del Aire contingent comprises five US-built McDonnell Douglas F/A-18 Hornet, twin-engine jets.

Estonia joined NATO in 2004, and aircraft from 17 different countries have taken part in the air policing role since then, according to BNS. The mission took on a new immediacy following the 2014 Russian annexation of Crimea.