Tens of thousands of people have taken to the streets in recent weeks in Baghdad and across the south demanding sweeping political change.
Two more Iraqi protesters have been killed in renewed clashes in the city of Karbala, a flashpoint in weeks of anti-government demonstrations, a protester and a medic said Wednesday.
They said the two were killed in overnight clashes near the provincial headquarters in the city. They spoke on condition of anonymity for fear of repercussions.
Tens of thousands of people have taken to the streets in recent weeks in the capital, Baghdad, and across the Shia south, demanding sweeping political change.
The protesters complain of widespread corruption, a lack of job opportunities and poor basic services, with regular power cuts despite the country's vast oil reserves.
The protesters have focused their anger on Shia political parties and militias, many of which have close ties to Iran . Across the south, they have attacked party and militia headquarters, setting some of them ablaze.
In Karbala, protesters attacked the Iranian consulate earlier this week, hurling firebombs over its walls.
Security forces killed at least three people and wounded several others as they dispersed the protest. Days earlier, masked men suspected of links to the security forces opened fire on a demonstration in Karbala, killing at least 18 people.
In the capital, Baghdad, protesters clashed with security forces on a fourth bridge across the Tigris River, after previous clashes forced the closure of three other bridges, paralysing traffic.
The protests have been centred in Tahrir Square, on the eastern bank of the Tigris, and the demonstrators have been trying to reach the Green Zone that is located on the other side, which houses government offices and foreign embassies.
The US Embassy in Baghdad issued a statement calling on the government to "engage seriously and urgently with Iraqi citizens who are demanding reform".
"We deplore the killing and kidnapping of unarmed protesters, threats to freedom of expression, and the cycle of violence taking place," it said. "Iraqis must be free to make their own choices about the future of their nation."
Iraqi security forces have killed at least 269 protesters in two major waves of demonstrations since early October.
Iraqi security forces shot dead at least 13 protesters between Monday and Tuesday.
After eight people were killed during the day on Monday, security forces shot dead at least five others overnight or early on Tuesday, including one killed with live fire toward a funeral procession held for another who died hours earlier, security and medical sources said.
Iraq's leaders have promised reforms and early elections, but the process they have laid out could take months, and the protests have only grown in recent days.