The Hajj, one of the five pillars of Islam, is due to end on Monday and it is an obligation for all Muslims to take part in the pilgrimage at least once in a lifetime, if they are physically fit and financially able.
The pilgrims dress in white and say the words "Here I am at thy service, oh Lord".
Before they leave Mecca, and after they have completed the Hajj, they must walk seven times round the Kaaba (a cube-like building in the centre of the city's Great Mosque) in an anti-clockwise direction.
Saudi Arabian authorities are imposing a strict quota system to try and keep the number of foreign visitors to a reasonable level.
