MOSCOW, Oct. 24 (Xinhua) -- Russian Aerospace Forces sent a battalion of S-400 missile defense systems and a squadron of Pantsir-S air defense missile-gun systems to Serbia for joint military drills, the Russian Defense Ministry said Thursday.

The units will appear in the second stage of the Slavic Shield 2019 air defense drills, which are running until Tuesday at the main Serbian military base of Batajnica, a ministry statement said.

During the drills, Russian and Serbian air defense units will jointly perform the tasks of detecting, tracking, classifying and destroying an entire spectrum of airborne targets of a conditional enemy in the process of carrying out joint combat air defense duty, it said.

The first stage of the drills was held in September this year at the Center for Combat Training and Combat Use of the Russian Aerospace Forces in the southern Russian region of Astrakhan.