Millions of pilgrims from around the world were in the holy Iraqi city of Karbala on the Arba’een, which marks the 40th day after the martyrdom anniversary of the third Shia Imam.

The pilgrims arrived in the city on foot, by cars, buses and many other means from Iraq, Iran, Saudi Arabia, Lebanon, Bahrain, Pakistan and countries as far as Nigeria, PRESS TV reports. The religious ceremony marks the 40th day after the martyrdom anniversary of the grandson of Prophet Mohammad(PBUH), Imam Hussain(PBUH). The Arba’een ceremony isthelargest religious gatherings in the world. Iraqi forces have tightened security to protect the pilgrims against terrorist attacks. The Iraqi government has also adopted measures for an easier evacuation of pilgrims from Karbala. Imam Hussain(PBUH) and his 72 companions were martyred in the battle of Karbala on the day of Ashura in 680 CE, after refusing to pledge allegiance to the tyrant ruler of his time.READ MORE:World’s Biggest Pilgrimage, And Why You’ve Never Heard of it!