Mourners packed the streets of Tehran on Monday for ceremonies to pay homage to top Iranian military commander Qasem Soleimani, who was killed in a U.S. strike in Baghdad on Friday.

The crowd gathered at Tehran University before supreme leader Ayatollah Ali Khamenei presided over prayers for the slain general. 

Soleimani, who spearheaded Iran's Middle East operations as commander of the Revolutionary Guards' Quds Force, was killed in a U.S. drone strike near Baghdad airport. His killing ratcheted up tensions between Tehran and Washington. 

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In freezing early morning temperatures, women in black walked alongside men holding up flags bearing the names of Shiite imams as they walked down Tehran's Enghelab Street towards the university. 

The procession was broadcast live on state television, with screens bearing a black ribbon across the top left hand corner in a rare tribute. Khamenei appeared to cry as he prayed over the flag-draped coffins containing the remains of Soleimani and five other "martyrs" killed in the strike. 

The supreme leader was flanked by Soleimani's son, the slain general's replacement as Quds commander Esmail Qaani, President Hassan Rouhani, parliament speaker Ali Larijani and the Guards' top commander Major General Hossein Salami. 

People prayed together with Khamenei, whose voice cracked as he spoke. 

The U.S. drone attack that killed Soleimani was ordered by U.S. President Donald Trump, who said the Quds commander had been planning an "imminent" attack on American diplomats and forces in Iraq. 

Mourners in Tehran formed a sea of black along Enghelab Street dotted with red Shiite flags and white signs. 

One of the placards held aloft by a man read "#hard_revenge". As they marched towards the university, a main artery of the Iranian capital, the mourners chanted "Death to America" and "Death to Israel" and waved flags of Iraq and Lebanon among others. 

The procession came after Soleimani's remains were returned to Iran on Sunday. They were paraded through the streets of the southwestern city of Ahvaz before being taken to second city Mashhad, in the country's far northeast. 

The Revolutionary Guards said the overwhelming number of mourners in Mashhad forced the cancellation of a ceremony that had been planned in Tehran on Sunday night.

(With input from AFP)