Iranians gathered on Saturday at the Imam Khomeini Grand Mosalla – Tehran’s largest prayer hall – as part of week-long funeral ceremonies for former supreme leader Ayatollah Ali Khamenei.
Large crowds are expected on the streets of the city, while authorities have closed airspace over the capital.
This is the first time since Mr Khamenei was killed on February 28 – the first day of the regional war – that civilians have been allowed to gather in such numbers.
Mourners at the prayer hall held aloft images of Mr Khamenei, who has been replaced as supreme leader by his son, Mojtaba. He has not been seen in public since his appointment and officials have said he is not expected to attend the events.
Some observers suggested the funeral events would offer an indication of the strength of support for the Tehran regime, after its war with the US and Israel. The government faced a major challenge from mass protests in January.
Foreign delegates arrive
A public procession is scheduled to take place in Tehran on Sunday as part of the ceremonies. On Monday, the coffin will be moved to the city of Qom, before being taken to Najaf and Karbala in Iraq.
The coffin will then return to Iran, with Mr Khamenei expected to be buried in the north-eastern city of Mashhad on July 9.
The funeral ceremonies began on Friday as dozens of foreign dignitaries paid their respects in Tehran. Among those in attendance were Pakistan's Prime Minister Shehbaz Sharif, army chief Field Marshal Asim Munir and Interior Minister Mohsin Naqvi, with their country having acted as a mediator in talks to end the war.
Iraqi President Nizar Amedi also travelled to Iran, while Lebanon sent Defence Minister Michel Menassa. Saudi Arabia, Egypt and Qatar were also represented.
Senior officials from Russia and China attended Friday's ceremony, which also attended by representatives of Iranian proxy groups including Lebanon's Hezbollah, Yemen's Houthi rebels and Gaza militant group Hamas.
