Afghan President Hamid Karzai in his message for Eid, the most important festival for Muslims marking the end of the fasting month of Ramadan, said the Islamic world was suffering.
"Hundreds of people are being killed every day in Islamic countries," he said, highlighting the plight of those in war-torn Gaza.
"The Afghan people are sad about the situation of people in Gaza Palestine, they are being killed ruthlessly day and night... we hope for peace, stability, development and happiness for them."
Festivities in Muslim-majority Malaysia were also muted -- with government officials cancelling their usual hosting of Eid feasts for the public -- following the downing of Malaysia Airlines flight MH17 over eastern Ukraine on July 17.
Two other passenger planes -- TransAsia Airways in Taiwan and Air Algerie in Mali -- also crashed last week. The aviation disasters come after the mysterious, as yet unsolved March disappearance of another Malaysia Airlines jet, MH370.
In his Eid message telecast late yesterday, Malaysian Prime Minister Najib Razak expressed his "extreme sadness, most profound sympathy and deepest condolences" to MH17 and MH370 victims' families, who struggle with their loss.
Diyana Yazeera, daughter of MH17 chief stewardess Dora Shahila Kassim, posted on Twitter late yesterday that Eid, referring to it in the Malay language as Raya, would not be the same.
"Mummy, this year's raya and the upcoming ones, well will not be raya. Im not gonna celebrate it without you," she posted. "Stop asking me to be strong. Its so hard to do."
In neighbouring Indonesia, the world's most populous Muslim nation, instead of celebrating, the family of MH17 passenger Ninik Yuriani were preparing to fly to Amsterdam, where victims' remains have been brought for identification.
"What was supposed to be a happy feast turned to deep sadness," her sister Enny Nuraheni, 54, told AFP. "We can plan all we want, but everything is in God's hands."
Yuriani, 57, who lived in Amsterdam, had planned to fly to Jakarta and then to her small village in central Java to celebrate Eid with her family.
In Pakistan's northwestern town of Bannu, where most of those driven from their homes by a military operation against Taliban militants have fled, 3,000 people offered Eid prayers at a park.
Cricketer-turned-opposition leader Imran Khan visited the town to distribute sweets, saying on Twitter that he was "determined" to be with those driven from their homes.