Iraqi security forces fired teargas and live bullets on Sunday in clashes with protesters who resisted with stones and petrol bombs, witnesses and security sources said.
More than 100 protesters were hurt, including at least 75 in the southern city of Nassiriya, in the renewed violence in Baghdad and other cities after the security forces tried to clear sit-in protest camps, medical sources said.
The protesters are demanding the removal of what they consider a corrupt ruling elite and an end to foreign interference in Iraqi politics, especially by Iran, which dominates state institutions.
Unrest resumed last week, after a lull of several weeks, following the US killing of Iranian Major-General Qassem Soleimani and an Iraqi paramilitary chief in Baghdad this month.
The killing, to which Iran responded with ballistic missile attacks on two Iraqi military bases, has revived tensions in Iraqi politics and delayed the formation of a new government.
In Baghdad, protesters were coughing and washing their faces and eyes to rid themselves of the effects of the gas while medical workers provided first aid, as the site was inaccessible to ambulances.
Tuk tuks evacuated wounded protesters in clouds of tear gas and black smoke from burning tyres.
Earlier Sunday, hundreds of university students had gathered in Tahrir square, the main protest camp, chanting slogans against the United States and Iran.
In the centre of Nassiriya, protesters set fire to two security vehicles and hundreds of other demonstrators controlled the city's main bridges. A police source described the situation in Nassiriya as tense and critical.
Protests also continued in the cities of Kerbala, Najaf and Diwaniya, defying attempts by security forces to end their months-long sit-in, witnesses said.
In other violence, five Katyusha rockets landed on Sunday night in Baghdad's Green Zone, which houses government buildings and foreign embassies, a military statement said. There were no immediate reports of casualties but a QNA report, quoting the Independent High Commission for Human Rights of Iraq, said 12 people were killed and 230 others injured in protests over the past three days.
Nine protesters were killed in the capital Baghdad and three others in the southern city of Nasiriyah.