A multi-day funeral for Ayatollah Ali Khamenei, killed in a US-Israeli attack, has begun in Tehran A week-long funeral for Iranian Supreme Leader Ayatollah Ali Khamenei has begun in Iran, with thousands of mourners urging the country’s authorities to exact revenge on the US and Israel for his killing.The burial ceremonies come more than four months after Khamenei was assassinated on February 28 at the very beginning of the latest US-Israeli aggression against Iran. He was killed in a concentrated airstrike on his official residence in Tehran alongside multiple relatives, including his son-in-law, daughter, and 14-month-old granddaughter.Coffins holding the remains of Khamenei and his family members have been put on display at the Imam Khomeini Grand Mosque in the Iranian capital, with top officials and foreign dignitaries paying their last respects.Thousands of mourners gathered outside the mosque, with many seen carrying Iranian national flags, as well as blood-red flags, an important symbol in Shia Islam. The flag, called the ‘Ya la-Tharat al-Husayn’ dates back to the late 7th century, when it was first raised after the Battle of Karbala in a call to avenge the death of Imam Husayn ibn Ali. Attendees were heard chanting “Death to America” and “Death to Israel,” as well as demanding “revenge” on those behind Khamenei’s assassination. The funeral is set to continue throughout the next week, with an estimated 30 million expected to participate in the mourning of Khamenei in Iran and neighboring Iraq, where more than half the population are Shia Muslims. READ MORE: Iran bids farewell to late supreme leader (PHOTOS, VIDEOS) Khamenei’s body will be transported through at least five cities, with the procession expected to visit multiple Shia shrines along the way, including the Iraqi cities of Karbala and Najaf, which are home to key Shia holy sites. The tour is set to end at the Shia holy city of Mashhad, where the late cleric was born.