A bus carrying Pakistani pilgrims overturned in central Iran, killing 28 passengers and injuring another 23 people, state media reported on August 21. The accident took place late August 20 in the central Iranian province of Yazd and was caused by a technical defect in the bus braking system, according to preliminary investigations made by the Iranian traffic police. Millions of Shi'ite Muslims are currently partaking in the Arbaeen pilgrimage in Iraq's Karbala Governorate. The event marks the 40th mourning following the martyrdom of Imam Hussein bin Ali, a central figure in Shi'ite Islam and the grandson of Prophet Muhammad.