At least 40 protesters have been reportedly killed in Iraq as security forces used tear gas and an Iranian-backed militia opened fire to try to quell renewed demonstrations against corruption and economic hardship, security sources say.

Key points: More than 2,000 people have been reportedly injured nationwide in the latest protests

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

Demonstrators are protesting against political elites they say have failed to improve their lives after years of conflict

More than 2,000 people were injured nationwide, according to medical sources and the Iraqi High Commission on Human Rights (IHCHR), 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 Ali Mohammed, 16, who had covered his face with a t-shirt to avoid inhaling tear gas, as chaotic scenes overwhelmed Baghdad's central Tahrir Square.

Young protesters draped in Iraqi flags chanted "with life and blood we defend you, Iraq".

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

Anti-government protesters burn police vehicles guarding the provincial council in Basra. ( AP: Nabil al-Jurani )

A series of clashes two weeks ago between protesters and security forces left 157 people dead and over 6,000 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.

The IHCHR said eight protesters were killed in Baghdad on Friday. At least five of them were protesters struck by tear gas canisters, according to security sources.

At five people were killed in Baghdad after being struck by tear gas cannisters. ( AP: Khalid Mohammed )

In the south, security sources said 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.

Eight people were killed in Amara city, including six protesters, one AAH member and one intelligence officer, according to police sources. Security sources reported three protesters were killed in oil-rich Basra, one in Hilla, and one in Samawa.

In Diwaniya city, twelve protesters died after being trapped in a burning building, according to security sources and morgue officials.

The building, which housed the local offices of the Iran-backed Badr Organisation, was apparently torched by protesters unaware that others were already inside.

Iraqi police fired live shots into the air as well as dozens of tear gas canisters to disperse protesters on the streets of Baghdad. ( AP: Hadi Mizban )

Interior Ministry spokesman Khalid al-Muhanna said at least 68 members of the security forces were injured.

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

They pose the biggest challenge to Prime Minister Adel Abdel-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.

Anti-government protesters try to break into the provincial council building during a demonstration in Basra. ( AP: Nabil al-Jurani )

Iraqis suffer poverty country's despite oil wealth

Despite Iraq's vast oil wealth, many of the country's citizens live in poverty and 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 country's elite as subservient to one or other of Iraq's two main allies, the US and Iran. Many suspect these powers use Iraq to pursue their struggle for regional influence via proxies unconcerned with ordinary people's needs.

The protests follow similar demonstrations earlier this month, when 157 people died. ( AP: Khalid Mohammed )

"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.

"We want Iran to take its parties and leave, America to take its parties and leave, and let the Iraqi people decide."

In Basra, footage showed protesters clashing with security forces who launched tear gas canisters and stun grenades and were met by rocks thrown at their vehicles. Young men carried the injured away as protesters set police cars on fire.

Anti-government protesters took cover as Iraq security forces fired during a demonstration in central Baghdad. ( AP: Khalid Mohammed )

A curfew was imposed until further notice in the southern provinces of Basra, Muthanna, Wasit, Babel and Dhi Qar after protesters torched offices of lawmakers, Shi'ite political parties and militia headquarters.

How the Government and security forces handled Friday's planned protests had been seen as a litmus test for the stability of the country, with political leaders already on edge.

Protesters Rage against the elite

In a Thursday-night address, Mr Abdel-Mahdi stressed that violence would not be tolerated and warned that any collapse of the government would drag Iraq into further turmoil.

Iraq's top Shiite cleric, Grand Ayatollah Ali al-Sistani, who in recent weeks criticised the Government's handling of the protests, urged calm on all sides during his sermon on Friday.

A government-appointed inquiry into the protests earlier this month determined that security forces had used excessive force. ( AP: Nabil al-Jurani )

In Baghdad, many demonstrators initially believed authorities would refrain from violence after security forces killed dozens of protesters earlier this month.

Hundreds tried throughout the day to march into the city's fortified Green Zone, which houses government buildings and foreign embassies, when they were stopped by security forces.

By afternoon, the mood had shifted, with thousands of angry protesters wrapped in Iraqi flags under pouring rain, chanting that they were peaceful and calling political leaders corrupt.

People were treated for injuries including tear gas exposure. ( AP: Khalid Mohammed )

As clashes broke out, tuk-tuks carried the injured to hospitals.

Medical sources said hundreds of people had been treated for injuries, most related to tear gas exposure.

Reuters