The coffin of former Iranian supreme leader Ali Khamenei arrived Friday at the religious complex in Tehran where an unprecedented funeral will take place, four months after his death in an Israeli-American strike.

Authorities expect between 15 and 20 million participants in Tehran alone for this three-day national tribute, which begins on Saturday and is intended as a show of strength after the war that killed many top leaders and thousands of civilians.

The body of Ayatollah Khamenei, wrapped in a flag bearing the colors of Iran, will be displayed day and night until Monday in the grounds of the Great Mosalla, a vast complex to which AFP has obtained rare access.

Its walls are covered with large portraits of the man who was supreme leader for more than three decades, black flags as a sign of mourning, and red flags, a symbol of martyrdom and revenge.

Ahmad Vahidi, the head of the Islamic Revolutionary Guard Corps, one of the most powerful military forces in the Middle East, came to pay his respects, according to images broadcast by Iranian media. Having remained discreet since the beginning of the war, likely to avoid being assassinated like his predecessor, this was his first public appearance.

"People will come from all over Iran. There will be a huge number of people," says Hossein Moghadassi, a 43-year-old worker busy on the site, while some are expected to start waiting as early as Friday evening for the doors to open at 06:00 on Saturday (02:30 GMT).

- Posters and slogans -

Ali Khamenei, the longest-serving supreme leader since the advent of the Islamic Republic in 1979, died at the age of 86 in bombings against his residence on February 28 by his two sworn enemies, the United States and Israel.

His state funeral, initially planned for March but postponed due to the war, is expected to be the largest in Iranian history.

In 1989, at the death of his predecessor Ruhollah Khomeini, approximately 10 million people attended his funeral, according to official figures. Crowd surges resulted in more than ten deaths.

Alongside Ali Khamenei's coffin are those of his relatives who were also killed on the first day of the war, including one of his daughters, a son-in-law, a daughter-in-law and a granddaughter.

A procession carrying the remains of the former supreme leader will parade through the streets of Tehran on Monday, where many posters and slogans pay tribute to the "martyr", before reaching the holy city of Qom on Tuesday.

- Under close surveillance -

The presence of Ali Khamenei's son, Mujtaba, who succeeded him as Supreme Leader in early March, has not been confirmed. Wounded in the strikes that killed his father, the leader only communicates through statements attributed to him and has not appeared in public.

Among the dignitaries expected to attend are leaders and officials from some thirty countries, mainly neighboring ones, including former Russian President Dmitry Medvedev and Pakistani Prime Minister Shebaz Sharif. China will be represented by a senior parliamentary official, He Wei.

No European leaders were invited.

"All those who will attend the funeral have sided with the right side of history," stressed Iranian Foreign Ministry spokesman Esmail Baghai this week, denouncing Western support for Israel and the United States in their two wars against the Islamic Republic, in June 2025 and this year.

Ironically, the start of the funeral will coincide with the United States' national holiday, which on July 4th celebrates its 250th anniversary.

These funerals are taking place under tension, in the context of a fragile ceasefire between Tehran and Washington, but also six months after major demonstrations against the high cost of living and the government.

Tehran has been like a fortress since Friday, with numerous security forces and a huge perimeter inaccessible by car.

Tehran's airport is partially closed on Friday and will be completely closed on Monday, a national holiday throughout Iran. Shopping malls have closed and businesses are on forced hiatus.

Ali Khamenei will be buried on July 9 in the holy city of Mashhad (northeast Iran), his birthplace. A religious leader, his coffin will be displayed on Wednesday in neighboring Iraq, where the Shiite community is also the majority.