A Russian Tu-95MS Bear strategic bomber crashed in the Khabarovsk region in the country’s Far East during a training exercise, the Russian Ministry of Defense announced Tuesday. The Tu-95MS is a large, four-engine strategic bomber and missile platform, which entered service with the Soviet Union in 1956, and is expected to be part of the Russian air force until at least 2040.

“On July 14 at 9.50 a.m. Moscow time [2:50 a.m. EDT] the Tu-95MS aircraft crashed while performing a scheduled training flight some 80 kilometers [50 miles] from Khabarovsk. The crew ejected,” Russia’s TASS news agency quoted the defense ministry as saying.

The aircraft was not carrying any ammunition allowance -- meaning it was unarmed -- when it crashed in a deserted area in Khabarovsk. A source told TASS that the crash occurred because three of the plane's propulsion systems failed. Khabarovsk lies nearly 500 miles north of the eastern city of Vladivostok.

Meanwhile, authorities reportedly deployed an Antonov An-12 aircraft and two Mi-8 helicopters to search for the seven crew members.

Tuesday’s incident came more than a month after the Russian Ministry of Defense grounded the entire fleet of Tu-95MS bombers after one of the planes overshot a runway while landing, and suffered an engine fire.

According to 2004 data, cited by military information site Globalsecurity.org, the Russian air force has 63 Tu-95MS bombers, and 42 of them are based at the Ukrainka airfield in the Amur region, where the June accident reportedly occurred during a practice flight.

Here is a video of a Russian Tu-95MS bomber in action:

Earlier this month, the entire Russian fleet of the SU-24 supersonic fighter jets was grounded after one plane crashed during takeoff in Khabarovsk near the Sea of Japan. The accident killed both pilots on board.

According to recent reports, Russia plans to upgrade at least 10 Tu-95MS strategic bombers -- capable of carrying nuclear missiles -- by 2016. The government also recently announced that nearly 70 percent of the Russian Armed Forces’ strategic aviation force would be modernized by 2020.

In May, Russia announced that it would buy at least 50 Tupolev Tu-160 “Blackjack” heavy strategic bombers, which would be produced simultaneously with the country’s new bomber, called PAK DA.

However, the announcements by Russian officials were deemed unfeasible by many experts, who said that the country does not have enough qualified personnel and funding necessary to support the predicted expansion.