Il Nuovo Postiglione - Huge crowds gather as Khamenei funeral ceremonies open in Iran

Iranian authorities say they anticipate between 15 and 20 million participants in Tehran alone over the next three days for tributes to the man who ran the country for three-and-a-half decades.

Six days of funeral ceremonies are planned to commemorate Khamenei, who ruled the Islamic republic as its number one from 1989 until his killing aged 86 on the first day of the US-Israeli war with Iran on February 28.

The events will be scrutinised in particular for any signs of Khamenei's son and successor Mojtaba Khamenei, who was named supreme leader a week after the killing of his father but is yet to appear in public.

Thousands of mourners entered Tehran's Grand Mosalla, filling the main courtyard of the vast religious complex Saturday morning, before funeral ceremonies officially start, AFP journalists witnessed.

Another AFP journalist saw mourners walking several kilometres to reach the venue. Hundreds of supporters of the Islamic republic were already waiting on Friday evening outside the Grand Mosalla.

"We want to say a final goodbye to our leader, which is why waiting like this isn't painful or difficult for us," Somayye Hamedi told AFP as she waited.

Significant security measures have been imposed, with roads blocked and airspace expected to be closed for what is set to be the largest-scale public event in Iran since the burial of Khamenei's predecessor Ruhollah Khomeini in 1989.

- 'Final goodbye' -

The coffin will lie in state until Monday, when a procession will pass through Tehran. On Tuesday it will move to the clerical hub of Qom, before moving on Wednesday to cities holy to Shia Muslims in neighbouring Iraq, then proceeding for burial on Thursday in Khamenei's home city of Mashhad in northeastern Iran.

Officials who survived the war showed their grief and displayed a united front on Friday, with parliament speaker and top negotiator in the US talks Mohammad Bagher Ghalibaf visibly tearful.

Top Iranian officials paying their respects included Ahmad Vahidi, who was named chief of the powerful Revolutionary Guards after his predecessor was killed in the same strikes that killed Khamenei but had not been seen since.

The coming days will be closely watched for signs of Mojtaba Khamenei, who has communicated only by written statements and is said to have been wounded in the same strikes, though the extent of his injuries was never made clear.

Other relatives killed in the strikes will also be buried, including Ali Khamenei's infant granddaughter.

International guests paying respects Friday included Pakistani Prime Minister Shehbaz Sharif, whose country has been mediating between Iran and the US, and Russian ex-president Dmitry Medvedev, now deputy head of the Russian security council, who attended on behalf of President Vladimir Putin.

Palestinian militant group Hamas and Lebanese Shia group Hezbollah, both backed by Tehran, were also represented, as was the Taliban government in Afghanistan.

- 'Call for vengeance' -

After five weeks of fighting, the Middle East conflict is on hold following an initial accord between Iran and the US. But Iranian officials have warned Tehran is ready to resume fighting if needed.

"The nation's call for vengeance must ring in the ears of the whole world," said Ghalibaf, who urged Iranians to turn out en masse.

Army chief Amir Hatami vowed Israel and the US "will pay for the blood of the martyred leader and all the nation's martyrs".

But authorities will also want the event to go smoothly, deeply aware of the risk of crowd crushes, which have marred similar events in the past, with TV broadcasting guidelines on how to stay safe.

With temperatures well over 35 degrees Celsius (95 degrees Fahrenheit) expected over the next few days in Tehran, tankers were stationed to spray water on the roads to cool down attendees.

Ahead of the ceremonies, AFP correspondents reported that Tehran was quieter than usual, with many normally busy streets free of Tehran's notorious traffic.

D.Campanella--INP