A c battle group consisting of five fighters took part in a joint air defense exercise in the Sea of Japan on Monday as part of the ongoing China-Russia joint naval drills, a military spokesman said.

Four fighter jets - two J-10 and two JH-7 - dispatched by the People's Liberation Army (PLA) Air Force took off from an airport in northeast China and returned after completing the drill, according to the Air Force spokesman Shen Jinke.

A KJ-200 early warning plane also took part in the exercise to give directions to the other four fighters, Shen said, adding that the exercise leveled up joint sea and air combat capabilities.

The drills, codenamed Joint Sea-2015 (II), are being held on Aug. 20-28 in the Peter the Great Gulf, waters off the Clerk Cape, and the Sea of Japan.

This is the second China-Russia naval exercise this year.

The last China-Russia naval drills, Joint Sea-2015 (I), were held in the Mediterranean Sea in May.