From war-ravaged Iraq and Syria to Ebola-hit Nigeria and dozens of other nations, pilgrims are converging on Saudi Arabia for the annual hajj, the world's largest Muslim gathering.
From early October, close to two million believers will congregate to follow the 1,400-year-old tradition of Islam's Prophet Mohammed.
"This is like a beautiful dream. I will never forget these moments," Iraqi pilgrim Kazim Ibrahim, 69, said after reaching the holy city of Mecca.
While Ibrahim and other pilgrims are united by a common religious bond, this year's hajj comes with Muslim nations drawn together by widespread revulsion toward the Islamic State group jihadists.
Saudi Arabia and four other Arab states have joined Washington in launching air strikes in Syria against the militants, who have declared a "caliphate" straddling Iraq and Syria and committed brutal atrocities.
Saudi Foreign Minister Prince Saud al-Faisal has branded IS "evil" and said the jihadists have distorted the image of Islam and Muslims.
Oil-rich Saudi Arabia is home to Islam's holiest sites, where it is waging a different kind of battle to protect pilgrims from two deadly viruses, Ebola and Middle East Respiratory Syndrome corona virus (MERS-CoV).
The deadliest Ebola epidemic on record has infected more than 6,200 people in west Africa and killed nearly half of them, according to the World Health Organisation (WHO).
Saudi Arabia is the country hardest hit by MERS, which last weekend claimed the life of a 27-year-old Saudi man in Taif, about 80 kilometres (50 miles) east of Mecca.
This brought to 317 the number of MERS deaths in Saudi Arabia since it first appeared in September 2012.
Research by Saudi scientists indicates that camels play a role in the transmission of the virus to humans.
In June the WHO said a surge in MERS cases had receded but countries should remain vigilant ahead of pilgrimages to Saudi Arabia.
With such a large group of people concentrated in a limited area for a short time, "the hajj season constitutes a factor increasing the likelihood of outbreaks or epidemics of infectious diseases," acting Health Minister Adel Fakieh said in a statement.
