The Russian Air Force's strategic, intercepting and special units have completed a strategic exercise over the eastern part of the country, the Russian defense ministry said on Thursday.

"The crews of the Tu-95MC bombers worked out suppressing the anti-aircraft defense of the conventional enemy as well as the strategic targets," Air Force spokesman Vladimir Deryabin told reporters here.

During their flights over the neutral zone of the Pacific Ocean, the Russian planes were watched by U.S. F-15 fighter jets, he noted.

The MIG-31 fighters and A-50 airborne warning and control system aircraft also conducted escorting exercises, he added.

According to Deryabin, participating planes received mid-air refueling four times during the drills, with the A-50 and MIG-31 aircraft staying in the air for up to 8 hours and the bombers for 17 hours.

The exercise, involving some 30 aircraft and over 200 servicemen, was held from Tuesday to Thursday, said the spokesman.