TEHRAN — Thousands of mourners gathered at the Imam Khomeini Mosalla Grand Mosque in Tehran on Saturday as Iran began week-long funeral ceremonies for former Supreme Leader Ayatollah Ali Khamenei.The ceremonies opened with the national anthem, Quran recitations and religious eulogies, Iran's state broadcaster IRIB reported.Khamenei's coffin was placed on public display in a glass enclosure, allowing mourners to pay their respects, according to the broadcaster.Khamenei was killed in U.S.-Israeli strikes on Iran that began on Feb. 28, followed by Iranian attacks.Citing Iran's national airline, IRIB reported that additional flights had been added on the Tehran-Mashhad route to accommodate increased demand from people traveling to attend the funeral ceremonies.Official memorial events began on Friday, with foreign leaders and official delegations from across the region and beyond paying tribute to the late Iranian leader.Among the senior foreign dignitaries attending were Russian Security Council Deputy Chairman Dmitry Medvedev, Turkish Vice President Cevdet Yilmaz, Iraqi President Nizar Amidi, Iraqi Parliament Speaker Mohammed al-Halbousi, Pakistani Prime Minister Shehbaz Sharif, Pakistani Senate Chairman Yousaf Raza Gillani, and Pakistani Army Chief Asim Munir.According to the official schedule, memorial ceremonies will continue in Tehran throughout the weekend with the participation of heads of state, senior officials and religious figures.Public farewell ceremonies are scheduled for July 4 and July 5, followed by the main funeral procession in Tehran on July 6.The funeral rites will then move to Qom on July 7 before continuing to Iraq on July 8, with ceremonies planned in Baghdad, Najaf and Karbala, where religious and political leaders are expected to receive the body before it is transferred to major Shia holy sites.The final funeral and burial ceremony is scheduled for July 9 at the Imam Ali Reza Shrine in the northeastern city of Mashhad.