Iraqi pilgrims celebrate Arbaeen in Karbala, south of Baghdad The annual Arbaeen pilgrimage sees millions of worshippers, mostly Iraqis and Iranians, converge by foot on Karbala, 100 kilometres (60 miles) south of Baghdad. Arbaeen marks the end of the 40-day mourning period for the killing of Imam Hussein, grandson of the Prophet Mohammed, by the forces of the caliph Yazid in 680 AD.\\n IMAGES AND SOUNDBITES