Saudi Arabia has barred more than 269,000 people without permits for the annual Hajj pilgrimage from entering Mecca this week, authorities said, as the world's largest annual gathering of people has officially begun.

A Saudi government spokesperson says more than 1.5 million foreign pilgrims are in the country for this year's Hajj.

Millions of Muslims from all over the world have converged on Mecca in Saudi Arabia to partake in Islam's annual Hajj pilgrimage.