The late supreme leader will be buried in his hometown, the eastern holy city of Mashhad.

Huge crowds have gathered in the eastern holy city of Mashhad as Iran prepares to bury its slain Supreme Leader Ayatollah Ali Khamenei.

The burial in Khamenei’s hometown on Thursday follows a week of mass funeral processions, rallies and mourning ceremonies held across Iran, including a day dedicated to neighbouring Iraq.

There were marathon ceremonies to project strength and unity amid the US-Israel war on Iran, which began with strikes by the two countries on Tehran that killed Khamenei and several of his relatives on February 28.

Despite a promised pause in US attacks, Khamenei’s burial ceremony comes after the US and Iran traded attacks for a second day.

After massive processions in Iraq’s holy cities of Najaf and Karbala, Khamenei’s remains arrived on Thursday at Mashhad international airport, footage shared by the official news agency IRNA showed.

Iraq’s paramilitary group Popular Mobilisation Forces (PMF), or Hashd al-Shaabi, said on Wednesday more than 2.3 million people took part in Khamenei’s funeral procession in Najaf alone.

Khamenei’s remains, along with those of four family members killed alongside him, were also paraded through Tehran and the Shia clerical centre of Qom.

The Tasnim news agency and the broadcaster Press TV reported that millions of mourners attended the funeral procession in Tehran, with Iranian officials describing the event as the “largest public gathering in the country’s modern history”.

Crowds marched through Mashhad on Thursday morning, waving Iranian flags, photographs of Khamenei and placards with revolutionary slogans.

The mourners also chanted slogans demanding vengeance against US President Donald Trump for his role in the assassination.

“I swear by the blood of the supreme leader, Trump, we will kill you,” they shouted, with women holding up placards reading “Kill Trump”.

The incumbent supreme leader, Mojtaba Khamenei, has been notably absent from the processions. He has not yet appeared in public since taking over days after his father’s assassination.

Officials have said he was wounded in the air strikes that killed his father, but the severity of his injuries remains unclear.

Iranian state television reported that Khamenei’s burial ceremony in Mashhad would be pushed to 2:30pm local time (11:00 GMT) as larger-than-expected crowds had delayed the funeral processions in Iraq.

Reporting from Tehran, Al Jazeera’s Resul Serdar Atas said Iranian officials had confirmed that the overnight US attacks on the Tehran-Mashhad railway line, which have put it out of service, had not delayed the burial ceremony.

Mohammad Mohammadi Golpayegani, head of the late leader’s office, said Khamenei had requested to be buried in Mashhad, near the shrine of Imam Reza, a descendant of the Prophet Muhammad.