Pilgrims stand at Mount Arafat on peak day of Haj.

More than two million pilgrims gathered at Mount Arafat on Monday for a vigil to atone for their sins and ask Allah’s forgiveness as the annual Haj pilgrimage in Saudi Arabia reached its climax.

Pilgrims clad in white robes signifying a state of purity spent the night in an encampment around the hill where Allah tested Prophet Ibraham’s (peace be upon him) faith by commanding him to sacrifice his son Prophet Ismail (peace be upon him) and Prophet Muhammad (peace be upon him) gave his last sermon.

Other worshippers praying in the nearby Mina area ascended in buses or on foot from before dawn as security forces directed traffic and helicopters and surveillance drones hovered overhead.

Some pilgrims carried umbrellas to protect themselves from the sun as temperatures surpassed 40°C after an evening of thunderstorms and high winds.

Men and women from 165 countries gathered side by side, while soldiers handed out bottled water and some people snapped selfies.

Pakistani pilgrim Mohamed Forqan, 30, said it was a great day to be a Muslim. “Here in Arafat we feel that we are born today asking Allah to forgive our sins,” he said.

Hilal Issa, 70, from Algeria, said he was praying for God to pardon all Muslims and save the Arab world from its afflictions.

Saudi Arabia has said more than 2.3 million pilgrims, mostly from outside Saudi Arabia, have arrived for the five-day ritual.

The pilgrims will spend the day on Mount Arafat.

By sunset they will move to the rocky plain of Muzdalifa to gather pebbles to throw at stone columns symbolising the devil at another location called Jamarat on Tuesday, which marks the first day of Eid Al Adha.

A new kiswa, the cloth embroidered with verses from the holy Quran, was placed over the holy Kaaba in Makkah’s Grand Mosque late on Sunday. Pilgrims will return to pray there at the end of Haj. In a midday sermon, senior Saudi cleric Sheikh Hussein bin Abdulaziz Al Al Sheikh also urged pilgrims to come together with their co-religionists but cautioned: “Haj is not a place for slogans and parties.”

Officials say they have taken all precautions this year, with tens of thousands of security forces and health workers on hand to maintain safety and provide first aid.

Pilgrimage is also the backbone of a plan to expand tourism under a drive to diversify the kingdom’s economy away from oil.

The Haj and year-round Umrah generate billions of dollars in revenue from worshippers’ lodging, transport, fees and gifts.