Two US civilians and two Afghan soldiers were killed Tuesday during a shooting by a suspected local army trainer inside a weapon training centre in northern Afghanistan, dpa quoted NATO as saying. One foreign soldier and an Afghan service member were injured in the shooting that happened during routine weapons training inside a military base near Mazar-e-Sharif, the capital for Balkh province, NATO-led International Security Assistance Force (ISAF) said in a statement. "The suspected individual was thought to be an Afghan Army trainer," the statement said, adding that one of two dead Afghans was believed to be the shooter. A joint investigation by Afghan and ISAF military officials was underway, it said. "The actions of this individual are not representative of the thousands of men and women who train and fight side-by-side with ISAF everyday to protect their fellow citizens from insurgent brutality," General Josef Blotz, an ISAF spokesperson said in the statement. The attack came a week after another "rogue" Afghan soldier killed three British troopers and injured four others in southern province of Helmand. Besides battling the resurgent Taliban fighters, the around 140,000 US and NATO troops are also tasked with training the Afghan security forces. The combined forces also work with Afghan troops in their operations.