Thousands of people have gathered outside the US embassy in Baghdad to protest against recent US air strikes on an Iran backed Iraqi militia.
The protesters marched into the heavily fortified Green Zone, chanting “Death to America” and burning US flags.
At least 25 fighters died when the US bombed bases associated with Kataib Hezbollah in Iraq and Syria on Sunday.
The US said it was retaliating for a rocket attack in Iraq on Friday that killed an American civilian contractor.
Iraqi Prime Minister Adel Abdul Mahdi said the air strikes had violated his country’s sovereignty and would force it to review its relations with the US.
Kataib Hezbollah’s commander, Abu Mahdi al-Muhandis, warned that the militia’s response “would be very tough on the American forces in Iraq”.
Iran described the attacks as a “clear example of terrorism”.