An estimated three million Muslims have begun leaving the Saudi Arabian city of Mecca to begin the annual Hajj pilgrimage amid enhanced security.

The authorities say they have implemented new safety measures to prevent stampedes that have killed hundreds of people previously. In January, almost 400 people were killed and some 300 injured in a stampede during one of the rituals.

The Hajj, one of the five pillars of Islam, is due to end on Monday. It is an obligation for all Muslims to undertake the pilgrimage at least once in a lifetime, if they are physically and financially able.

The massive convoy is making its way to the nearby tented city of Mina, the pilgrims’ home over the next few days. The pilgrims are following the route of the first Hajj performed by the Prophet Mohammed. BBC reporter Aleem Maqbool is among the worshippers and says the day has been emotional, with many beginning the pilgrimage in tears.

The Saudi authorities are imposing a strict quota system to try to keep the number of foreign visitors to a manageable level.

When the pilgrims return to Mecca, they must perform a precise series of steps - including walking seven times round the Kaaba (a cube-like building in the centre of the mosque) in an anti-clockwise direction.

At the last Hajj, earlier this year, at least 345 pilgrims died in a crush during the stone-throwing ritual of the pilgrimage.

The stampede took place at the foot of the bridge of Jamarat, in Mina, where pilgrims hurl stones at three pillars representing the spot where the devil is said to have appeared to Abraham, and which creates a dangerous bottleneck.

Since then a major rebuilding project has been undertaken and 50,000 security personnel have been mobilised.

The ritual has seen many lethal stampedes, but the number of dead in January was the highest in 16 years.