The Grand Mosque, with a capacity of one million pilgrims, overflowed with worshipers at each of the five daily prayers, the Arab News reported. Praying pilgrims even crowded the streets leading to the mosque.
Authorities have increased security for the five-day Haj, deploying additional forces in Mecca and other holy sites.
Interior Minister and Chairman of the Supreme Haj Committee Prince Naif inspected the final preparations Tuesday and issued a strong warning against anybody trying to undermine Haj security.
"We are ready for anything that could happen," he told a press conference in the tent city of Mina.
Authorities have warned that domestic pilgrims who do not carry Haj permits would be stopped at checkpoints.
About 1.4 million foreign pilgrims have arrived in Saudi Arabia to take part in the Haj