MOSCOW, April 8 (RIA Novosti) – Modernized MiG-31BM interceptor aircraft have started combat alert duty at an airbase in Tver Region in western Russia, with the full modernization of the unit to be completed by the end of the year, a military spokesperson said Tuesday.

“In Tver region two modernized Mig-31BM interceptors have started their combat alert duty in the Western Military District,” said Col. Oleg Kochetkov, the head of the district’s press service, adding that the aircraft were delivered at the end of last year.

“By the end of 2014, the Khotilovo MiG-31 squadron will be fully re-equipped with the newer modification of the interceptors,” the colonel said.

The MiG-31BM is a two-seat supersonic long-distance interceptor aircraft developed by the Russian aircraft corporation MiG. It features upgraded avionics, a 320 km detection range and a strike radius of 280 km. The plane’s multimode radar can detect up to 24 targets simultaneously, engaging up to eight at the same time.

The air fleet upgrades are part of a series of modernization efforts by the Russian Defense Ministry.