An Iraqi Shiite militia claimed a drone attack Monday targeting US troops at the airport in Iraq's capital, Baghdad, further widening the retaliation over the killing of Iran's Supreme Leader Ayatollah Ali Khamenei.

The group, Saraya Awliya al-Dam, is one of a group of Shiite militias operating in Iraq following the 2003 US-led invasion of the country that toppled Saddam Hussein.