The Russian Defense Ministry has deployed three MiG-31E warplanes equipped with Kinzhal hypersonic missiles to the far western Kaliningrad exclave, according to Russian media.
The ministry was quoted as saying by the Russian state-owned news agency RIA Novosti on August 18 that the aircraft would be on round-the-clock duty.
Russia has long boasted about its arsenal of Kinzhals, which have a range of up to 2,000 kilometers, and fly 10 times the speed of sound.
Kaliningrad, a Russian region located between NATO members Poland and Lithuania, became a flashpoint in June after Vilnius imposed restrictions on Russian goods traveling across its territory to the exclave, arguing it was applying sanctions imposed by the European Union after Russia's invasion of Ukraine on February 24.
Earlier on August 18, Finland's Defense Ministry said that two Russian MiG-31 jets were suspected of violating its airspace near the city of Porvoo, on the Gulf of Finland 150 kilometers from Russia.