At least 40 protesters were killed in Iraq when security forces used tear gas and an Iranian-backed militia opened fire to try to quell renewed demonstrations against corruption and economic hardship.

A government intelligence officer and a member of the powerful Asaib Ahl al-Haq militia were killed in a clash with protesters in the southern city of Amara, police sources said.

More than 2000 people were injured nationwide as demonstrators vented frustration at political elites they say have failed to improve their lives after years of conflict.

“All we want are four things: jobs, water, electricity, and safety. That’s all we want,” said 16-year-old Ali Mohammed who had covered his face with a T-shirt to avoid inhaling tear gas, as chaotic scenes overwhelmed Baghdad’s central Tahrir Square.

Sirens wailed and tear gas canisters landed amid groups of young protesters draped in Iraqi flags and chanting “with life and blood we defend you Iraq.”

The bloodshed is the second major bout of violence this month.

An Iraqi protester flashes the v-sign during clashes with riot police forces near the local government headquarters following a demonstration in Karbala in southern Iraq. Photo: AAP

A series of clashes two weeks ago between protesters and security forces left 157 people dead and over 6000 wounded.

The unrest has broken nearly two years of relative stability in Iraq, which lived through foreign occupation, civil war and an Islamic State (IS) insurgency between 2003 and 2017. It is the biggest challenge to security since IS was declared beaten.

On Friday, eight protesters were killed in Baghdad, the Iraqi High Commission on Human Rights (IHCHR) said. At least five of them were protesters struck by tear gas canisters.

In the south, at least nine protesters were killed when members of the Iranian-backed Asaib Ahl al-Haq (AAH) militia opened fire on protesters who tried to set fire to the group’s office in the city of Nasiriya, according to security sources.

Eight people were killed in Amara city, another three protesters were killed in oil-rich Basra, while in Diwaniya city, twelve protesters died after being trapped in a burning building.

The sometimes violent demonstrations erupted in Baghdad on October 1 and spread to southern cities.

They pose the biggest challenge to Prime Minister Adel Abdul Mahdi since he took office just a year ago. Despite promising reforms and ordering a broad cabinet reshuffle, he has so far struggled to address the protesters’ discontent.

Despite the OPEC member country’s vast oil wealth, many Iraqis live in poverty, have limited access to clean water, electricity, basic healthcare or decent education as the country tries to recover from years of conflict and economic hardship.

Many Iraqis view the elite as subservient to one or other of Iraq’s two main allies, the United States and Iran. Many suspect these powers use Iraq to pursue their struggle for regional influence via proxies unconcerned with ordinary people’s needs.

“They hit us last night and again this morning. We don’t have any demands anymore, we want the government toppled,” said demonstrator Salah Mohammad.

-AAP