Russian defense contractor Almaz-Antey will deliver five sets of the S-400 missile systems by October this year, Sputnik News reported, citing newspaper Izvestia. The locations of the systems’ deployment are yet to be announced.

Five sets of SA-21 Growler missile systems, also known as S-400 Triumf in Russian, will reportedly enter into service with the country’s defense ministry in the same month. Chief executive of Almaz-Antey Yan Novikov told Izvestia that the 12th regimental set has been fully made and is being configured.

"Works preparing to transfer the S-400 ‘Triumf’ systems to the Ministry of Defense is planned to be completed ahead of schedule. The Ministry of Defense will receive the 12th, 13th and 14th regimental kits by the end of September, and 15th and 16th in the course of October 2016," Novikov told Izvestia, according to Sputnik.

Meanwhile, the S-400 Triumf missiles have been deployed on combat duty in Serbia, Tass news agency reported Tuesday. "The anti-aircraft missile regiment of the Novosibirsk air defense formation received the S-400 Triumph systems at the end of 2015. Crews of the Novosibirsk formation of the Central Military District’s Aerospace Forces have successfully completed the training course for the new weapons systems and had field firing practice at a range in the Astrakhan region, Southern Russia. The S-400 missile system crews took up combat duty today. The S-400 will replace the S-300PT Favorit systems," Major General Vladimir Korytkov said, according to Tass.

The S-400 Triumf is the latest long-range anti-aircraft missile system that went into service in 2007 and is designed to destroy aircraft, cruise and ballistic missiles, including medium-range missiles. The systems can also be used against ground objectives and can reportedly carry three different types of missiles.