US forces stationed at Erbil International Airport were attacked by two drones late on Saturday evening – the 20th anniversary of the 9/11 attacks that led to the American invasion of Iraq. The US began countermeasures to "defeat the drones", said coalition spokesman Col Wayne Marotto. No injuries were reported and no property was damaged. One drone caused an impact inside the perimeter of the base, while another did so outside. "Each attack against the GoI [Government of Iraq], KRI [Kurdistan region], and the coalition undermines the authority of Iraqi institutions, the rule of law and Iraqi national sovereignty. These attacks endanger the lives of civilians, and the partner forces from the ISF [Internal Security Forces], Peshmerga and coalition," said Col Marotto. The US on Saturday marked the 20th anniversary of the 2001<a href="https://www.thenationalnews.com/world/9-11-anniversary/" target="_blank"> attacks on New York and the Pentagon</a>, which killed thousands and led to the invasion of Afghanistan and, later, Iraq. Since 2003, 4,431 US personnel have died in Iraq and tens of thousands were wounded. There is no official tally of Iraqi deaths. Kurdish counter-terrorism force confirmed the attack was carried out using explosive-laden drones. "There are no victims in the attack carried out by two armed drones," the statement read. Erbil airport, which is also the base for a coalition of anti-extremist forces, was not damaged, said its director Ahmed Hochiar. The security forces sealed off access to the airport, witnesses said. No group has yet claimed responsibility. Erbil's airport has come under attack several times in the past year, in some cases by drones carrying explosives. Booby-trapped drones were used against the airport in July but they failed to cause casualties or damage. Last March, <a href="https://www.thenationalnews.com/mena/iraq/erbil-attack-iran-made-rockets-used-to-kill-contractor-and-wound-us-soldier-1.1166807" target="_blank">a rocket attack killed a civilian contractor</a> working with the US-led military coalition and wounded six others, including an American service member. A group calling itself Saraya Awliya Al Dam claimed responsibility for the March attack. Little is known about the group or its capabilities but it is thought to be tied to Asaib Ahl Al Haq, a powerful Iran-backed Shiite militia in the government-sanctioned Popular Mobilisation Forces. Experts said Saraya Awliya Al Dam appeared to be one of the dozens of new organisations probably tied to Iran that have <a href="https://www.thenationalnews.com/mena/iraq/shadowy-militia-organisation-likely-backed-by-iran-claims-fatal-iraq-attack-on-us-base-1.1166839" target="_blank">emerged and claimed responsibility for attacks against international forces</a> in Iraq over the past 18 months. US officials have blamed past attacks on Iran-aligned Shiite militias. In December 2019, a militia attack killed a US contractor in Iraq, sparking a series of American air strikes and militia retaliation. The US then killed Iranian Quds Force leader <a href="https://www.thenationalnews.com/world/mena/how-qassem-suleimani-provoked-the-us-with-covert-attacks-in-iraq-1.959728" target="_blank">Qassem Suleimani</a> in January last year, leading to a huge Iranian missile attack on US bases in Iraq that left dozens of American soldiers with brain injuries but caused no deaths. US forces are leading an international military coalition whose mandate is to help Iraqi troops fight the remnants of Isis.