Thousands of people have rallied in the Iraqi capital to mark the second anniversary of the killing of a revered Iranian commander and his Iraqi lieutenant in a drone attack by the United States.

Chanting "Death to America”, the marchers filled a Baghdad square to honour Iran’s General Qassem Soleimani, who headed the Quds Force, the foreign operations arm of the elite Revolutionary Guard, until his death on January 3, 2020.

"US terrorism has to end”, read one sign at the rally by backers of the pro-Iranian Hashed, also known as the Popular Mobilisation Forces (PMF), a former paramilitary alliance that has been integrated into Iraq’s state security apparatus.

"We will not let you stay after today in the land of the martyrs,” another placard read. US and Israeli flags were strewn on the ground, with people trampling them.

Al Jazeera’s Mahmoud Abdelwahed said the protesters are using the rally as an opportunity to reiterate their demands of full withdrawal of US and foreign troops from Iraq.

"Thousands of protesters, members of Iraq’s Popular Mobilisation Forces were chanting against the US and the presence of US troops in Iraq,” he said, speaking from Baghdad.

"They are blaming the [Iraqi] government for what they consider is collaborating with US forces,” he continued, "and that there hasn’t been any clarity or any transparency in the investigation over the past two years since the killing of General Qassem Soleimani and Abu Mahdi al-Muhandis.”

Supporters of Iran-aligned Shia factions were bussed in from various Iraqi provinces to the rally in Jadriyah, near the headquarters of the powerful armed groups.

Former US President Donald Trump ordered the attack that killed Soleimani near Baghdad’s airport along with his Iraqi lieutenant, Abu Mahdi al-Muhandis, Hashed’s deputy.

Trump had then said the assassination came in response to a wave of attacks on US interests in Iraq.

The killing of Soleimani – the architect of Iran’s Middle Eastern military strategy – and al-Muhandis sent shock waves across the region and sparked fears of a direct military confrontation between decades-old enemies Washington and Tehran.

Days later, Iraq’s parliament passed a non-binding resolution calling for the expulsion of all foreign troops from Iraq.

Iran, which wields considerable influence in neighbouring Iraq, warned it would avenge Soleimani’s death.

Five days after the killing, Iran fired missiles at an air base in Iraq housing US troops and another near Erbil in the north.

Since then, dozens of rockets and roadside bombs have targeted Western security, military and diplomatic sites across Iraq.

Iraqi and Western officials have blamed hardline pro-Iran factions for the attacks, which have never been claimed by any group.

In February last year, the US carried out an air raid against Kataeb Hezbollah, an Iranian-backed Iraqi paramilitary force stationed along the Iraqi-Syrian border, following rocket attacks on its Baghdad embassy and a US military contracting firm north of the capital.

Hashed has repeatedly called for the withdrawal of US troops who are deployed in Iraq as part of a multinational coalition fighting the ISIL (ISIS) group.

Senior Hashed official Faleh al-Fayyad reiterated the demand Saturday, saying the killing of Soleimani and al-Muhandis was "a crime against Iraqi sovereignty”.

In December, Iraq announced the end of the "combat mission” there of the US-led coalition against ISIL. But about 2,500 American soldiers and 1,000 coalition troops will remain deployed in Iraq to offer training, advice and assistance to national forces.

"We will not accept anything less than full withdrawal as revenge for the blood of our martyrs,” said Hadi al-Ameri, head of an Iran-aligned coalition.