TEHRAN (Dispatches) -- The Islamic Revolution Guards Corps (IRGC) launched a military exercise Sunday in northwestern Iran as part of annual events held to mark the beginning of the 1980-1988 war with Iraq.  
 The maneuvers, centered in the Oshnavieh border region, will include artillery, armored and airborne units, state broadcaster IRIB reported.
They involve practicing of defensive preparedness by infantry, armored, electronic warfare, and rocket units, as well as the ground-operating squadrons of the IRGC.
Iran’s northwest has repeatedly witnessed inroads by terrorist and anti-revolutionary elements and hence constitutes a focus of the IRGC’s counter-terrorism operations. Clashes with PJAK militant groups based in Iraq are a frequent occurrence in the border area.
In Tehran, the IRGC displayed the country’s sophisticated S-300 air defense system for the first time in public.
The show in Tehran’s Baharestan square near the Parliament building square exhibited different missile systems, including ballistic missiles, solid-fuel surface-to-surface Sejjil missiles and the liquid-fuel Ghadr.
The IRGC prepared the show for the annual Defense Week, marking the 37th anniversary of the 1980s invasion of Iran by the former Iraqi dictator Saddam Hussein.
Also on Sunday, Iran’s Army unveiled three new achievements in the area of artillery fire, named as Heydar 7, 41, and 44 Projects, in the presence of Brigadier General Kioumars Heydari, the commander of the Army's ground forces.
Picture taken on September 24, 2017 shows a ceremony featuring the unveiling of achievements made in the area of artillery fire by Iran’s Army. (Photo by IRNA)
Heydar 7 comprises an eight-wheel drive vehicle, equipped with a new turret and a 23-millimeter gun.
Heydar 41 features a 122-millimeter howitzer, fitted with an automatic magazine loader, shorter combat readiness process, and remote activation capability.
Heydar 44 has witnessed a 122-millimeter rocket launcher system being made smart and automated, resulting in sped-up and more precise fire, as well as its becoming interconnected with frontline surveillance drones, suitable for installment on all artillery systems.