Eleven pro-Iran fighters were killed in US air strikes on Syria carried out in retaliation for a drone attack that left an American dead and wounded six others, a war monitor said Friday. A US contractor was killed, and another contractor and five US service personnel were wounded when a kamikaze drone “of Iranian origin” struck a maintenance facility on a base of the US-led coalition near Hasakeh in northeastern Syria, the Pentagon said. In response, US Defense Secretary Lloyd Austin said Thursday that, at President Joe Biden’s direction, he had ordered “precision air strikes tonight in eastern Syria against facilities used by groups affiliated with Iran’s Islamic Revolutionary Guard Corps”. “The air strikes were conducted in response to today’s attack as well as a series of recent attacks against coalition forces in Syria by groups affiliated with the IRGC,” Austin said. The Syrian Observatory for Human Rights, a Britain-based monitor with a wide network of sources on the ground in the war-torn country, said 11 people had been killed by US strikes, including two Syrians. “US strikes targeted a weapons depots inside Deir Ezzor city, killing six pro-Iran fighters, and two other fighters were killed by strikes targeting the desert of Al-Mayadin, and three others near Albu Kamal,” said the Observatory’s head Rami Abdel Rahman. The United States deploys about 900 troops in bases and posts across northeastern Syria as part of the international coalition fighting remnants of the Islamic State group (IS). Iran-backed militias have a heavy presence across Syria, especially around the border with Iraq and south and west of the Euphrates in Deir Ezzor province, where the latest US strikes took place. American troops also support the Syrian Democratic Forces (SDF), the Kurds’ de facto army in the area, which led the battle that dislodged IS from the last scraps of their Syrian territory in 2019. The US personnel are frequently been targeted in attacks by militia groups. Two of the US service members wounded on Thursday were treated on-site, while the three other troops and one US contractor were medically evacuated to Iraq, the Pentagon said. “We will always take all necessary measures to defend our people and will always respond at a time and place of our choosing,” said General Michael Kurilla, commander of US Central Command. When the strikes were announced, Biden had already travelled to Canada, where he is set to meet with Prime Minister Justin Trudeau.