Millions of Iranians gathered in Tehran on Monday for the funeral and mourning rally of former Supreme Leader Ayatollah Ali Khamenei, who was killed in a joint U.S.-Israeli attack on February 28. The procession began early in the morning at the Grand Mosalla religious complex, where Khamenei’s body had been kept for two days for public tribute. His coffin was later brought to Freedom Square as mourners, dressed in black and carrying red flags symbolizing revenge, vowed to avenge his death.

State media IRIB described the gathering as one of the largest in modern history, with streets of Tehran overflowing with mourners. The funeral followed days of national mourning that began on Friday, attended by foreign dignitaries. Security was tightened across the capital amid warnings of overcrowding. Khamenei’s son and current Supreme Leader Mojtaba Khamenei did not attend due to security threats from Israel.

The funeral procession will continue through Qom and Iraq before Khamenei’s burial in Mashhad on Thursday. Iranian authorities view the massive turnout as a message of strength and resistance following the recent war with the United States and Israel.