Millions of pilgrims from across the world have started the annual Hajj pilgrimage by heading towards Mina, the vast tent city near Makkah, where spiritual chants of “Labbaik Allahumma Labbaik” echoed through the valleys on Monday.

The flow of pilgrims into Mina continued throughout the day as worshippers prepared to spend the night there before moving towards Arafat on Tuesday, the 9th of Dhul Hijjah, for Wuquf-e-Arafah — considered the most important pillar of Hajj.

Saudi authorities said elaborate arrangements had been made to ensure the comfort and safety of pilgrims during the sacred journey. Special facilities including shaded areas, cooling fans, mist spray systems and expanded medical services have been installed across the holy sites to help worshippers cope with the harsh weather conditions.

According to official figures, more than 1.5 million international pilgrims have already arrived in Makkah, with the majority travelling by air from different parts of the world.

Meanwhile, Saudi Arabia’s meteorological department warned that an intense heatwave is expected to continue during the Hajj days. Temperatures in and around Makkah could rise up to 47 degrees Celsius, while humidity levels may remain near 40 percent. Dusty winds are also expected in some areas.

Officials urged pilgrims to avoid unnecessary exposure to sunlight, drink plenty of water and strictly follow health and safety instructions to prevent heat-related illnesses during the pilgrimage.