The Iraqi government warned Monday that its relations with the United States were at risk after deadly American air strikes against a pro-Iran group sparked anger on the streets, with protesters torching US flags.
Baghdad said it would summon the US ambassador while Washington responded by accusing Iraqi authorities of having failed to "protect" US interests.
At least 25 fighters were killed in Sunday night's attacks, which saw US planes hit several bases belonging to the Kataib Hezbollah, one of the most radical factions of of the Popular Mobilization Forces (PMF), a Tehran-backed Iraqi paramilitary coalition.
The attacks came as Iraq is caught up in mounting tensions between its allies Tehran and Washington while it also grapples with huge street protests against corruption and Iran's growing political influence in the country.
US Secretary of State Mike Pompeo said in a call with UN Secretary-General Antonio Guterres that the US strikes “were aimed at deterring Iran,” the State Department said in a statement.
The air strikes will force Iraq to reconsider working with the US-led international coalition against ISIS, the Iraqi National Security Council said in a statement.
The raid "killed 25 and wounded 51, including commanders and fighters, and the toll could yet rise," said the PMF.
Victims were still being pulled from the rubble of bases near Al-Qaim, an Iraqi district bordering Syria, on Monday, it said.
The Kataib Hezbollah said they will hold a mass funeral ceremony on Tuesday in Baghdad near the high-security Green Zone, where the US embassy is located.
Iraq's government, acting in a caretaker capacity following the resignation of prime minister Adel Abdel Mahdi in the face of street protests, denounced the strikes and warned they could affect ties with Washington.
"American forces acted on their political priorities, not those of the Iraqis," a statement said, adding that such strikes "violate the sovereignty of Iraq".
The attacks "force Iraq to review its relations and its security, political and legal framework to protect its sovereignty", the government added.
The warning came as demonstrators torched US flags in the Shiite-dominated southern cities of Basra and Najaf as well as in Kirkuk, north of Baghdad, while lawmakers called for US troops to be booted out of Iraq.
Dozens of lawmakers called on the government to review an agreement allowing the deployment of 5,200 US soldiers in the country, saying the strikes amount to a violation that renders the pact obsolete.
US Assistant Secretary of State David Schenker said the strikes were a "proportionate" response for the death Friday of a US civilian contractor in Kirkuk in a Kataib Hezbollah rocket attack.
"We don't want an escalation here, we want a de-escalation," he added however.
Abdel Mahdi said he had been forewarned by US Defense Secretary Mark Esper that the US would carry out the attacks.
"He told me the United States would strike the Kataib Hezbollah and I told him it would be a very dangerous act that could lead to an escalation," Abdel Mahdi said.
Tensions have soared between the United States and Iran since Washington pulled out of a multilateral nuclear agreement with Tehran last year and imposed crippling sanctions
Iraqi leaders fear their country could become a battleground between Tehran and Washington.