Millions of Muslims today celebrated the festival at the end of the holy month of Ramzan, marked this year by a series of deadly jihadist attacks.
The three-day Eid al-Fitr festival traditionally means family gatherings and the exchange of gifts and sweets after a month of fasting from dawn until dusk.
But a wave of attacks in Muslim countries -- from Turkey and Bangladesh to Iraq and Saudi Arabia -- have made this year's Eid a sombre occasion.
Tens of thousands of worshippers gathered for Eid prayers at Islam's second-holiest site, the Prophet's Mosque in the Saudi city of Medina, just two days after a suicide bombing that killed four security guards in a nearby carpark.
Addressing the crowd, Sheikh Abdelbari al-Thabiti said the bombing was an "odious crime" carried out by "a group that no longer respects the rites of Allah or the sanctity of the Prophet's Mosque."
In Baghdad, Eid was overshadowed by a massive suicide car bombing on Sunday that ripped through the Shiite-majority Karrada district and left at least 250 dead.
Today Iraqis placed thousands of candles along sidewalks and in the charred remains of a building at the site of the blast.
Some prayed or read the Koran; others laid flowers and Iraqi flags or hugged and wept.
If it were a normal Eid "people would be happy and this street would be open, and people would be walking on it," Mohammed Al Sultan told AFP at the site of the bombing.
Across the border in war-torn Syria, the army said it would observe a 72-hour nationwide ceasefire coinciding with Eid.
Many of the attacks throughout Ramzan were claimed by or blamed on the Islamic State group.
Analysts fear that defeats in its Syrian and Iraqi strongholds are pushing the group to launch more attacks further afield.
In Bangladesh today, an eerie silence pervaded the diplomatic quarter of Dhaka five days after the IS-claimed killing of 20 hostages at a popular cafe.
The run-up to Eid usually sees malls packed with shoppers. But today many of the area's popular restaurants and shopping centres remained closed.
In Pakistan, thousands of worshippers attended Eid al-Fitr prayers at a mosque in Karachi.
Hundreds also gathered at an open-air mosque in the Nigerian capital Lagos to pray.
A seven-year insurgency by Islamist group Boko Haram in northeastern Nigeria has left at least 20,000 people dead and more than 2.6 million homeless.
About 150,000 people also attended morning prayers at the Al-Aqsa Mosque in annexed east Jerusalem, according to the Islamic Waqf organisation which is responsible for the mosque compound, the third-holiest site in Islam.
