Iran has begun six days of funeral ceremonies for late Supreme Leader Ayatollah Ali Khamenei, with thousands of mourners gathering at Tehran's Grand Mosalla to pay their respects. Khamenei, who was killed in US and Israeli strikes on Iran on February 28, was laid in a casket draped with the flag of the Islamic Republic and topped with his black turban. The coffins of several family members, including his 14-month-old granddaughter, were placed alongside him. Authorities expect between 15 and 20 million mourners to participate in funeral ceremonies across Iran and Iraq. Crowds carried red banners associated with calls for revenge and chanted slogans including "death to America" and "revenge". The funeral ceremonies come amid heightened regional tensions and uncertainty over the future of Iran's leadership and its relations with the United States and Israel.