Tears flowed and prayers filled the air as the annual Muslim hajj pilgrimage by almost two million faithful from around the world reached its zenith Friday on a vast Saudi plain.

"I am now a newborn baby and I don't have any sin," Nigerian pilgrim Taofik Odunewu told AFP, tears streaming down his face.

He stood at the foot of Mount Arafat and raised his hands to the heavens in the seamless two-piece white "ihram" outfit of male pilgrims.

"I pray for prosperity, long life and... I pray for my country," Odunewu said with a broad smile on the second day of the hajj.

An insurgency by Boko Haram Islamist militants has claimed thousands of lives in Nigeria.

The hajj, which officially ends on Tuesday, is the world's largest Muslim gathering.

It is one of the five pillars of Islam that every capable Muslim must perform at least once, the high-point of his or her spiritual life.

Hundreds of thousands of pilgrims arrived at Arafat on Friday carrying suitcases and other luggage among thousands of white tents which stood ready to accommodate the multitude.

From early morning, pilgrims crowded onto the slippery, rocky hill where Prophet Mohammed is believed to have given his final sermon 14 centuries ago.

The pilgrims pushed forward to touch the rocks during prayer, their attire turning the hill, which is also known as Mount Mercy, white in colour.

All male pilgrims dress in white ihram to symbolise a state of purity, which also emphasises their unity regardless of social status or nationality.

Some pilgrims sat alone on the rocks, praying silently, but others gathered in groups, their voices in a loud appeal to God.

But for Syrian pilgrim Mohammed al-Hammoud, this was a chance to make a political statement.

He climbed Mount Arafat and waved the flag of rebels who have spent three years fighting Syrian President Bashar al-Assad.

Hammoud, who was smuggled out of Syria to Turkey before reaching Saudi Arabia, said he "prayed for God to unite the fighters' ranks and grant them victory".


'This way, hajji'

Saudi Interior Minister Prince Mohammed bin Nayef said the hajj had attracted almost 1.4 million foreign pilgrims from 163 nations.

Local media report that several hundred thousand Saudis are also participating, pushing the total towards two million.

Security forces were deployed en masse across Mount Arafat and its plain to organise the wave of humanity.

"This way, hajji. Don't stop here. You're blocking the way," security men shouted through loudspeakers, trying to control the crowds.

Ali al-Shemmari, a soldier stationed at the hill, said "things are going well" despite some language difficulties between the pilgrims and Saudi security officers.

The number of faithful appeared lower than past years following a crackdown by authorities on illegal pilgrims without permits, more than 145,000 of whom have been turned away, state media said.

This year's hajj comes with Saudi Arabia and four other Arab nations joining Washington in air strikes against Islamic State group militants, who have committed a spate of atrocities in Syrian and Iraqi territory they seized.

"These criminals carry out rapes, bloodshed and looting," Saudi Arabia's top cleric said, without naming IS, during a Friday address at Mount Arafat.

Grand Mufti Sheikh Abdul Aziz al-Sheikh called on Muslim leaders to "hit with an iron hand the enemies of Islam", whom he called a threat to the religion.

Saudi authorities are also striving to protect pilgrims from two deadly viruses, Ebola and the MERS coronavirus.

No such cases have been recorded among the hajj visitors, officials say.

As the sun set on Arafat, pilgrims in their hundreds of thousands walked, rode motorbikes, or even climbed onto the roofs of buses for the journey to nearby Muzdalifah.

The sound of helicopters overhead and police sirens on the ground merged with the chanting of the faithful.

At Muzdalifah they gather pebbles for the symbolic "stoning of the devil" ritual on Saturday.

At the same time, animals will be slaughtered for Eid al-Adha, the feast of sacrifice celebrated by Muslims worldwide.