Hundreds of Iranians have chanted "Death to the treacherous House of Saud" outside the Saudi embassy as the Islamic republic's leader demanded Riyadh apologise for the deadly hajj stampede.
The protesters numbering around 400, some throwing tomatoes and watermelons at the embassy walls, were outnumbered by police who erected tall crowd control barriers to keep them back from the compound on Sunday.
The demonstration came after the toll from Thursday's stampede in Mina, near Mecca, rose to 769 pilgrims. At least 155 fatalities at the hajj were Iranian and a further 48 remain in hospital.
Iran's supreme leader Ayatollah Ali Khamenei demanded Saudi Arabia apologise for the disaster.
"Instead of passing the buck and playing a blame game, the Saudis should accept their responsibility and apologise to the world's Muslims and the bereaved families," he said.
Iran has been fiercely critical of the Saudi authorities' handling of safety and questioned whether the kingdom was fit to carry on organising the annual pilgrimage.
Khamenei's statement came just hours after Saudi Foreign Minister Adel al-Jubeir hit back at criticism from its regional rival, saying it "shouldn't play politics with a tragedy".
Iran's Culture Minister Ali Jannati plans to head a delegation to Saudi Arabia to follow up on 316 Iranians that Tehran says are missing, but state news agency IRNA said his team still has not received visas.
On Saturday, Tehran summoned Saudi Arabia's charge d'affaires for the third time since the stampede, to press the kingdom for greater cooperation.
Iran's President Hassan Rouhani appealed for UN mediation with the Saudis in a meeting with Secretary General Ban Ki-moon in New York, state television reported.
"Sadly, Riyadh isn't offering enough cooperation on the missing pilgrims and the transfer of the dead and injured," it quoted Rouhani as saying.
"It is crucial that the UN remind Riyadh of its legal and humanitarian obligations."