American military officials launched overnight strikes on 85 targets in Iraq and Syria in apparent revenge after the deaths of three US soldiers in Jordan.
Sixteen people were killed, among them civilians, and 25 injured in overnight attacks on pro-Iran targets in Iraq, prime minister Mohammed Shia al-Sudani's office said on Saturday.
In a statement, it condemned the strikes as a "new aggression against Iraq's sovereignty" and denied that they were coordinated by the Baghdad government beforehand with Washington, calling such assertions "lies".
The presence of the US-led military coalition in the region "has become a reason for threatening security and stability in Iraq and a justification for involving Iraq in regional and international conflicts", the statement added.
An Iraq official said: "This aggressive strike will put security in Iraq and the region on the brink of the abyss, and it also contradicts efforts to establish the required stability.
"Iraq reiterates its refusal to let its lands be an arena for settling scores, and all parties must realize this.
"Our country’s land and sovereignty are not the appropriate place to send messages and show force between opponents."
The country's foreign office spokesperson Nasser Kanaani, in a statement, said the attacks represented "another adventurous and strategic mistake by the United States that will result only in increased tension in instability in the region".
The US military launched airstrikes against more than 85 targets linked to Iran's Revolutionary Guard (IRGC) and the militias it backs, in retaliation for last weekend's drone attack in Jordan that killed three US troops.
The IRGC was set up shortly after the 1979 Islamic Revolution to protect the Shiraite clerical ruling system and provide a counterweight to the regular armed forces.
It has an estimated 125,000-strong military with army, navy and air units. It also commands the Basij religious militia, a volunteer paramilitary force loyal to the clerical establishment that is often used to crack down on anti-government protests.