Muslim pilgrims retrace prophet's path as haj starts

Millions of Muslims have begun the haj pilgrimage to Mecca in Saudi Arabia. Over two million Muslim pilgrims have already arrived in the holy city of Mecca amid a vast security operation to prevent militant attacks, deadly stampedes or political activities that could embarrass Saudi Arabia. The Haj symbolically retraces the route Prophet Mohammad took 14 centuries ago. The Saudi government has warned pilgrims not to politicise the haj. There have been deadly clashes between police and pilgrims and between different Islamic factions in the past.