Millions of Shiite Muslims observed the annual Arbaeen pilgrimage Tuesday in the Iraqi holy city of Karbala, under the shadow of ongoing regional tensions and fears of another round of escalation in the U.S.-Iran war.
Arbaeen is held 40 days after Ashoura, which commemorates the killing of Imam Hussein, grandson of the Prophet Muhammad, and members of his family, at the Battle of Karbala in 680 A.D.
