Nearly five months after Hassan Nasrallah was killed in an Israeli airstrike, thousands of supporters of the longtime leader of Lebanon's militant Hezbollah group have flown into Beirut for his funeral on Sunday.

Nasrallah was killed on Sept. 27 when Israel's air force dropped more than 80 bombs on Hezbollah's main operations room in southern Beirut. It was the biggest and most consequential of Israel's targeted killings in years.

The death of Nasrallah, one of the Iran-backed Shiite group's founders and the organization’s leader of more than 30 years, was a huge blow to the group he had transformed into a potent force in the Middle East.

Hezbollah, which the United States and some of its allies have designated a terrorist organization, has suffered significant losses in the latest war with Israel, including the killing of several of its most senior military and political figures.

Nasrallah's cousin and successor, Hashem Safieddine, who was killed in an Israeli airstrike on a Beirut suburb a few days later, will be laid to rest in his hometown in southern Lebanon. The two had temporarily been buried in secret locations. Hezbollah earlier this month announced plans for their official funerals.

Crowds are expected to gather Sunday at Beirut's main sports stadium for a funeral ceremony before Nasrallah's interment.

Flights from Iraq, where Hezbollah has a huge following among Iraqi Shiites, have been full for days. According to an Iraqi Transportation Ministry official, who spoke on condition of anonymity to discuss the flights, up to 6,000 people have flown to Beirut recently.

Nasrallah, idolized by his supporters and with large followings among the Shiites and the Islamic world, also held the title of sayyid, an honorific meant to signify the Shiite cleric's lineage dating back to the Prophet Muhammad, the founder of Islam.

However, Lebanese authorities revoked permission for a passenger plane from Iran, leaving dozens who had wanted to attend the funeral stranded in Tehran and triggering protests by Hezbollah supporters in Lebanon.

The ban came after the Israeli army accused Iran of smuggling cash to Hezbollah by way of civilian flights, leading some in Lebanon to allege that their government had caved in the face of a threat from Israel.

Some of those who were expected to fly in from Iran were now coming to Lebanon via Iraq. Also, members of Iran-backed groups in the region also were traveling to Beirut to attend Nasrallah's funeral.

Kazim al-Fartousi, spokesperson for the Iran-backed Kataib Sayyid al-Shuhada group in Iraq, arrived on Friday. He said Nasrallah was "the father, commander and the book that we read every day to learn about freedom."

Republican U.S. Representative Joe Wilson criticized Lebanese politicians who were planning to attend the funeral.

"Any Lebanese politician who attends the funeral of the murderous terrorist Hasan Nasrallah is standing with the Iranian Regime," Wilson said on X.