A policeman and seven protesters died in Nasiriyah as security forces clashed with demonstrators and four more people died in Amarah, according to medical and police sources.
At least 18 have now been killed since protests turned violent two days ago.
Live bullets and tear gas were used as a few hundred young demonstrators – some with weapons such as metal rods – gathered in central Baghdad on Thursday.
Explosions were also heard inside the heavily-fortified Green Zone, home to foreign embassies and government offices, though the US-led coalition said none of its forces or assets were hit.
A protester holds live round casings and a spent tear gas canister
An Iraqi security official, speaking on condition of anonymity, said two mortar shells had hit the area but landed in open space.
The unrest in Iraq started on Tuesday in Baghdad’s Tahrir Square, where small protests over the lack of jobs, local services and claims of corruption saw two people killed when security forces used bullets, tear gas and water cannon.
A child was among five more killed on Wednesday and hundreds have been injured, including police officers.
Locals in Baghdad say authorities have shut down social media sites such as WhatsApp, Facebook and Twitter – used to organise the protests – while there are also reports the internet is out in much of the country.
The unrest in Baghdad has centred around the central Tahrir Square
People are protesting over claims of corruption, lack of jobs and poor basic services
Heavily armed security forces and riot police blocked roads on Wednesday, putting up barbed wire in places, and black smoke hung over the city as protesters set fire to tyres and bins.
Iraq’s prime minister, Adel Abdul Mahdi, held a national security meeting and a 5am curfew was imposed in Baghdad.
Authorities say it is designed to “protect general peace” and protect protesters from “infiltrators” who want to attack police and property.
Ambulances, hospital workers, government employees and people travelling to and from the airport are exempt.
The protests are the biggest against the government since Mr Abdul Mahdi came to power nearly a year ago and the most significant since September 2018.
They have so far been centred on Baghdad and mainly Shia provinces in the country’s south, and appear to be without political leadership.
Many university graduates are believed to be involved, frustrated at the lack of jobs in the country as well as poor access to basic services such as water and electricity.
