TEHRAN (AFP) — Mourners beat their chests and chanted “revenge, revenge” as thousands gathered in Tehran early Saturday for a final farewell to slain supreme leader Ayatollah Ali Khamenei.

Khamenei, who ruled Iran for more than three decades, was killed in United States-Israeli attacks in late February that sparked a regional war.

His body lay in state on Saturday morning at the sprawling Grand Mosalla prayer complex in the Iranian capital, where an Agence France-Presse (AFP) journalist saw crowds filing in holding red flags, a symbol of revenge in Shiite Islam.

“We have come not for the funeral but for revenge,” a eulogist at the event chanted. “We’re never going to give up your blood, which is the reddest line.”

The mourners, some in tears, made their way through strict security towards the courtyard where Khamenei’s coffin was placed for people to pay their respects.

“We must rise up and, God willing, avenge the blood of our leader,” Hamidreza Shabani, an 18-year-old student, told AFP.

The coffin, wrapped in an Iranian flag, was unveiled on a stage from behind dark blue velvet drapes after Quran recitations. It stood on a raised platform accompanied by the coffins of his family members also killed in the US-Israeli attack.

Two rows of Iranian flags lined the stage, while portraits depicting different stages of Khamenei’s life hung on the walls of the Grand Mosalla.

Some mourners carried portraits of Iran’s new supreme leader Mojtaba Khamenei, who has succeeded his father but remained out of public sight.

Also seen among the crowds was the yellow flag of the Iran-backed militant group Hezbollah, which has been battling Israeli forces in southern Lebanon since the war broke out.