ASHULUK (Astrakhan Region) - The defense ministers of the Commonwealth of Independent States arrived Wednesday at the Ashuluk firing range in south Russia for the final day of a joint annual exercise.

Units of the ex-Soviet countries' joint air defense system will conduct live firing as part of the Combat Commonwealth 2007 drills in the Astrakhan Region near the Caspian Sea, which began on August 14.

Russian Deputy Air Force Chief Lieutenant General Vladislav Stytsenkov said: "During the joint CIS air defense exercises, more than 20 ground-to-air and air-to-air missiles will be fired."

"The principal goal of the live firing is to repel a simulated massive attack on the joint CIS air defense system by a potential foe," he said.

Russian Defense Minister Anatoly Serdyukov and the defense ministers of other CIS countries are attending the exercise, which is part of the second stage of Combat Commonwealth 2007.

The exercise involves live intercepts of dummy cruise missiles by S-300 (SA-10 Grumble) and S-125 (SA-3 Goa) air defense systems and a variety of simulated air missions performed by over 30 Su-24 Fencer, Su-25 Frogfoot, Su-27 Flanker and MiG-29 Fulcrum aircraft.

The third and fourth stages of the exercise will take place at Kazakh and Uzbek training grounds later in August and September, and will involve Kazakh and Uzbek Air Force and Air Defense units.

Conducted annually, the exercises are part of efforts to build a joint air defense shield for the CIS, a loose association of former Soviet republics. An integrated air defense network was set up by 10 CIS-member countries February 10, 1995, but so far exists only on paper.