BAGHDAD - Iraq's prime minister condemned on Friday the US killing of Iranian Quds Force commander Qassem Soleimani and Iraqi militia commander Abu Mahdi al-Muhandis and said it would "light the fuse" of war.

• 'US strike' killed top Iran, Iraq commanders at Baghdad airport: Hashed military force

The United States killed Soleimani, head of the elite Quds Force and architect of Iran's spreading military influence in the Middle East, in a strike at Baghdad airport. Muhandis, an adviser to Soleimani, was also killed.

"The assassination of an Iraqi military commander who holds an official position is considered aggression on Iraq ... and the liquidation of leading Iraqi figures or those from a brotherly country on Iraqi soil is a massive breach of sovereignty," Iraqi Prime Minister Adel Abdul Mahdi said.

Abdul Mahdi, whose government has the backing of Iran, said in a statement the US airstrike was "a dangerous escalation that will light the fuse of a destructive war in Iraq, the region, and the world."

The prime minister resigned in November due to anti-government protests but remains in office in a caretaker capacity. At least 450 people have been killed in the unrest, some which was driven by anger at Iranian influence in Iraq.

The prime minister said the US strike violated terms of the US military presence in Iraq, adding that US troops were exclusively in Iraq to train Iraqi security forces and fight Islamic State within the framework of a global coalition.

Abdul Mahdi called on parliament to convene an extraordinary session to "take legislative steps and necessary provisions to safeguard Iraq's dignity, security and sovereignty."

He did not specify what those provisions would entail, but some officials and parliamentarians have called for steps to expel US troops from Iraq.

Abdul Mahdi, whose government has support from Iran's and Tehran-backed Iraqi allies, described Soleimani and Muhandis as "huge symbols of the victory against Islamic State terrorists."

Iraq's Popular Mobilization Forces (PMF), a grouping of mostly Iran-backed Shi'ite Muslim militias led by Muhandis, helped security forces retake a third of Iraq from Islamic State. The grouping's troops were later incorporated into Iraq's official armed forces.

Thousands of Iraqis have taken to the streets since Oct. 1 to condemn, among other things, militias and their Iranian patrons that support Abdul Mahdi's government.

The protesters have also demanded an overhaul of a political system they see as corrupt and keeping most Iraqis in poverty.