Iran's supreme leader Ayatollah Ali Khamenei led prayers for late president Ebrahim Raisi on Wednesday as huge crowds thronged the capital Tehran for his funeral procession. Flanked by top officials, Khamenei said prayers over the coffins of the eight dead from Sunday's helicopter crash, who also included foreign minister Hossein Amir-Abdollahian. A sea of mourners filled the open space around Tehran university, where the prayers were held before the funeral procession moved on to Enghelab and Azadi squares. State television said Raisi, who had been widely seen as Khamenei's most likely successor as supreme leader, had received a "millionfold farewell" from the people of Tehran. "We have lost a prominent personality. He was a very good brother. He was an efficient, competent, sincere, and serious official," Khamenei told visiting Iraqi Prime Minister Mohamed Shia al-Sudani. The leader of Palestinian group Hamas, Ismail Haniyeh, joined the procession, as did the deputy leader of Lebanese group Hezbollah, Naim Qassem. "I say once again... we are sure that the Islamic Republic of Iran will continue its support for the Palestinian people," Haniyeh told the crowd to chants of "Death to Israel". - Foreign guests - Iran's acting president, Mohammad Mokhber, later received heads and representatives of countries in the Middle East, North Africa, Asia and Europe. Tunisian President Kais Saied and Qatari Emir Tamim bin Hamad al-Thani attended an afternoon ceremony in which around 60 countries took part, said state news agency IRNA. Egypt's top diplomat, Sameh Shoukry, was also at the ceremony. He is the first Egyptian foreign minister to visit Tehran since the 1979 Islamic Revolution. Member countries of the European Union were among the absentees of the ceremony while some non-member countries, including Belarus and Serbia had their representatives. In the capital, huge banners have gone up hailing the late president as "the martyr of service", while others bade "farewell to the servant of the disadvantaged". Tehran residents received phone messages urging them to join the funeral procession. "I was sad, I came to calm my heart and calm the heart of the supreme leader," said one mourner who gave her name only as Maryam and said she had travelled from Varamin, south of Tehran, to pay her last respects. Raisi's helicopter crashed into a fog-shrouded mountainside in northwestern Iran on Sunday as his entourage headed back to the city of Tabriz after attending a ceremony on the border with Azerbaijan. A huge search and rescue operation was launched, involving help from the European Union, Russia and Turkey. State television announced Raisi's death early on Monday. The Iranian military said Wednesday that domestically produced drones had played the key role in locating the crash site. - Burial in Mashhad - Funeral ceremonies for Raisi and his entourage began on Tuesday with processions through Tabriz and the Shiite clerical centre of Qom drawing tens of thousands of black-clad mourners. From Tehran, the bodies will be taken to Iran's second city of Mashhad, Raisi's hometown in the northeast, where he will be buried on Thursday evening after funeral rites at the Imam Reza shrine. Khamenei, who wields ultimate authority in Iran, has declared five days of national mourning and assigned vice president Mohammad Mokhber, 68, as caretaker president until a June 28 election for Raisi's successor. Iran's top nuclear negotiator Ali Bagheri, who was Amir-Abdollahian's deputy, has been named acting foreign minister. The country's armed forces chief Mohammad Bagheri has ordered an investigation into the cause of the helicopter crash. Raisi was elected president in 2021, succeeding the moderate Hassan Rouhani at a time when the economy was battered by US sanctions imposed over Iran's nuclear activities. The ultra-conservative's time in office saw mass protests, a deepening economic crisis and unprecedented armed exchanges with arch-enemy Israel. After his death, Russia and China sent their condolences, as did NATO, while the UN Security Council observed a minute's silence. Messages of condolence also flooded in from Iran's allies around the region, including the Syrian government as well as Hamas and Hezbollah.