MINA, Saudi Arabia - Muslim pilgrims threw pebbles at a stone wall outside Mecca, shaved their heads and bought sacrificial animals on Wednesday, the third day of the annual haj pilgrimage to the Mecca area.

Many arrived for the pebble-throwing ritual with swollen feet and sore legs after walking about 20 km (12 miles) during the night, stopping for a few hours of sleep in the rough in the Muzdalifa area, where they collected at least 49 pebbles.

They were coming from the plain of Arafat, where the haj reached its climax on Tuesday afternoon, a period of waiting and private prayer until sunset gives the signal for the more than 2 million pilgrims to leave for Mecca.

After the three main duties on Wednesday -- the pebbles, the shaving and the sacrificial animal -- the male pilgrims can take off the two pieces of white cloth they put on when they went into a state of ritual purity on Monday morning.

The stone-throwing ritual has been the most dangerous stage in an event which has seen a series of tragic accidents in recent years, as easy air travel and increasing prosperity add to the pressure on the Saudi government to grant more pilgrim visas.

More than 1.6 million people entered Saudi Arabia for the event this year, about the same as last year. With pilgrims from inside the country -- Saudi and foreign workers -- the total number is well over 2 million; some Saudi media said 3 million.

On Wednesday pilgrims had the choice of three walkways to approach the stone and concrete wall, a modernized version of what used to be a stone pillar. The ritual represents defiance of the devil and commitment to resisting his temptations.

LINGERING DANGERS

The Saudi authorities have added the two upper levels to relieve the crowding on the ground level, where 362 pilgrims died in the crush in January 2006, the worst haj tragedy in 16 years. But not all the pilgrims were happy.

Fadel Marhoon, an Islamic studies teacher from Bahrain, said the new walls or pillars, known in Arabic as the jamarat, were so big that pilgrims often threw their stones from afar, endangering those in front of them.

"If you go close and then turn back when you're finished, you might get hit in the face," he said.

Abbas Mubarak, a Shi'ite Muslim from Ahsa in eastern Saudi Arabia, said Shi'ites had to cope with the most severe crowding at the lower level because their clerics have decreed that throwing pebbles from the upper levels does not count.

The two pilgrims criticised the crowding of vehicles in the Muzdalifa area overnight, which made it hard for pedestrians to walk towards Mecca. Drivers had trouble too, some spending 12 hours between Arafat and Mina.

At Mina, barbers set up shop in the street to shave the heads of the most enthusiastic pilgrims. Other pilgrims made do with a severe haircut, often carried out in the street with nail scissors plied by a friend or relative.

Most pilgrims do not see the animals they buy for slaughter. They buy a coupon from a kiosk and trust that the Saudi authorities will oversee the process of killing the beast and shipping it abroad for distribution to the poor. Sheep, cows and camels are the usual choices.

This year the jamarat opened at midnight and some pilgrims reached Mecca in the early hours of the morning. There they carried out the same rituals they performed earlier in the process -- walking seven times around the stone shrine called the Kaaba and seven times along a nearby walkway.

They have to go back to the jamarat on Thursday and Friday for further stoning ceremonies.