Eid-ul-Fitr is being celebrated in Saudi Arabia with millions of faithful from around the world offering prayers in Grand Mosque and Majid-e-Nabvi on Friday.
The grand mufti, in his sermon after the prayers, urged unity and sacrifice for the poor and the needy among the faithful.
He said salvation of mankind lies in following the commandments of Allah and the teachings of the Prophet Muhammad (PBUP).
He prayed may Allah Almighty create mutual love and harmony in the world of Islam.
Eid-ul-Fitr is being celebrated in Middle East, Egypt and Jordan, Europe and Americas on Friday. However, in many European countries and Americas, followers of some sects will mark Eid on Saturday.
In Libya, the religious authorities based in the capital of Tripoli, announced Eid celebration on Saturday, while in the eastern part, run by a rival administration, authorities marked the festival on Friday.
In Pakistan and India, Eid will be celebrated on Saturday.
Meanwhile, in Afghanistan, the head of the Taliban-appointed judiciary, Abdul Hakim Haqqani, announced Eid-ul-Fitr would fall on Friday.
As the moon could not be sighted on Thursday in Phillippines, the country will celebrate Eid on Saturday.
But, In Indonesia, the country with the largest Muslim population, religious affairs minister announced on Thursday that Eid would be celebrated on Saturday.
In some countries with a Shiite Muslim majority, authorities have announced Eid would be celebrated on Saturday.
Statements from Iran's supreme leader Ayatollah Ali Khamenei and Iraq's highest Shiite authority, Grand Ayatollah Ali Sistani, said Eid would be celebrated on Saturday in their countries.
In Oman, too, the religious festival would be marked on Saturday.