MINA, Saudi Arabia — In sweltering temperatures, Muslim pilgrims in Mecca converged on a vast tent camp in the desert on Friday, officially opening the annual Hajj pilgrimage. Ahead of their trip, they circled the cube-shaped Kaaba in the Grand Mosque, Islam's holiest site.

More than 1.5 million pilgrims from around the world have already amassed in and around Mecca for the Hajj, and the number was still growing as more pilgrims from inside Saudi Arabia joined. Saudi authorities expected the number of pilgrims to exceed 2 million this year.