A decorated truck moves slowly through the crowd. Flag-draped coffins stand on the truck bed, and people dressed in black crowd below.
In the sea of people, Iranian flags wave side by side with homemade signs. "We will kill Trump," several read. In Tehran's Imam Hossein Square, the day began with the hanging of an effigy of the US president, according to state-run Iranian media.
"We are not here to say goodbye, we are here for revenge. And we will take revenge," Fatima Hassan, one of the mourners in the capital, told the AP news agency.
Fell out of the coffin
Temperatures are expected to be well above 30 degrees Celsius in Tehran on Monday. Crowds along the procession route are being sprayed with water, according to images published by the state-run Iranian news agency Fars. According to the AP, mourners are being urged via loudspeakers to walk slowly and not to push.
The authorities hope to avoid the chaos that characterised the funeral of Khamenei's predecessor Ruhollah Khomeini in 1989. Then, about 10 people died and more than 10,000 were injured in crowds that attracted several million people.
The Ayatollah's body also fell out of the coffin when the crowds stormed the hearse.
The successor is not visible.
The coffins of Ali Khamenei and four family members, all killed in US-Israeli attacks on the first day of the war, are now on their way to Tehran's Mehrabad airport. Ceremonies will then be held in Qom and the Iraqi cities of Najaf and Karbala, before Khamenei is finally laid to rest in his hometown of Mashhad on Thursday.
Ahead of today's procession, the Supreme Leader's coffin has been lying in state in the Grand Mosque complex in Tehran for two days.
On Sunday, three of the ayatollah's sons made a rare public appearance, but Mojtaba Khamenei, who succeeded his father, is still conspicuous by his absence.
