The grassroots protest movement has been the largest Iraq has seen in decades -- but also the deadliest, with more than 400 people killed since early October, and 15 others shot dead on Friday in the flashpoint city of Nasiriyah.

Thursday was also one of the bloodiest days yet, with 44 demonstrators killed and nearly 1,000 wounded in Baghdad and across the south.

"France strongly condemns the excessive and disproportionate use of force against protesters in Baghdad and the southern cities," a statement from the French foreign ministry said.

"France reaffirms its commitment to the right to demonstrate peacefully and calls on all parties to refrain from any act of violence," it added.

Iraqi Prime Minister Adel Abdel Mahdi announced he would resign on Friday just hours after the country's top cleric urged parliament to replace the cabinet.

Abdel Mahdi would be the first prime minister to step down since Iraq became a parliamentary system following the US-led ouster of Saddam Hussein in 2003.

"France continues to accompany and support Iraq, its authorities and the Iraqis in this crucial period for the democratic future of the country," the statement added.