Shiite Muslims have begun converging on Karbala, Iraq, ahead of Arbaeen, the annual commemoration marking 40 days after the martyrdom of Imam Hussein, the Prophet Muhammad’s grandson. Photographs from the shrine show devotees reaching toward the tomb as religious authorities prepare for one of the world’s largest pilgrimages. Governments in Pakistan, where the day is observed as Chehlum, say security plans are in place for processions scheduled on 15 August. Police in Karachi will escort the main march leaving Nishtar Park, while officials in Rawalpindi and Hafizabad report heightened patrols, road closures and surveillance to protect participants.