IRAQ PROTESTS: DEATH TOLL RISES TO 20 AS UNREST SPREADS IN SOUTH

The death toll in three days of mass anti-government protests in Iraq has risen to 20 with hundreds more injured as the government-imposed curfew in several cities failed to prevent the unrest from spreading in the country's south.

Braving live fire, tear gas and local curfews, Iraqis angry at high unemployment and entrenched corruption gathered in the streets for a third day in the biggest challenge yet to Prime Minister Adel Abdel Mahdi, who will complete one year in office next month.

The embattled prime minister ordered a ban on all movement across the capital starting at 5:00am (0200 GMT), but dozens of protesters defied the order and gathered in Baghdad's emblematic Tahrir (Liberation) Square.

"We slept here so the police don't take the place," one demonstrator told AFP before riot police fired into the air in a bid to disperse them at Tahrir Square in central Baghdad.

Travellers to and from Baghdad airport, ambulances, government employees in hospitals, electricity and water departments, and religious pilgrims are exempt from the curfew, the statement said.

Curfews were also imposed in the holy city of Najaf on Wednesday after security forces fired on protesters who are demanding an end to rampant power cuts, water shortages and state corruption.

The southern city of Nasriya, which has seen so far the deadliest protests with a total of eight protesters and one police officer killed, has also been placed under curfew.

Another protester was shot dead on Thursday in the province of Dhi Qar, regional health chief Abdulhussein al-Jaberi said. 

In the city of Amarah, medics and security forces have confirmed the killing of four protesters on Thursday, bringing the death toll over the past three days to 20.

More than 400 others have been wounded in the nationwide protests.

Demonstrations over similar issues engulfed the southern city of Basra last summer and effectively ended previous prime minister Haider al-Abadi's chances of a second term.

Early on Thursday, some cars and civilians were seen in the capital's streets. Speaking two kilometres from Tahrir Square, the focal point of protests, Al Jazeera's Imran Khan said there was an"eerie quiet over Baghdad" but that he could hear "sporadic gunfire towards Tahrir Square".

"What we are hearing from protesters themselves is that come 3 pm local time (1200  GMT) they will try and push towards Tahrir Square," Khan said. "So the scene is being set between the protesters and the Iraqi security forces."

Residents are wary that more protests could erupt after powerful Shia leader Muqtada al-Sadr called for "a general strike".

Al-Sadr's political bloc, Saeroon, which came first in last May's parliamentary elections, is part of the ruling coalition.

The demonstrations have descended into violence as security forces responded to protesters by firing tear gas, rubber bullets and live rounds.

"There was no spark for these protests," Khan said. After a small protest was quickly dispersed by security forces on Tuesday, a social media call went out which resulted in thousands of people taking to the streets, he added.

The protesters are mostly "angy young people who are not aligned to any political or religious party", Khan said.

"They are simply very frustrated at the fact that they don't have jobs," he said.

Meanwhile, two border crossings to Iraq - including one widely used by Iranian pilgrims - have been closed because of unrest in Iraq, Iranian border guards said.

According to Iran's semi-official news agency Mehr, Iranian border guards commander General Qasem Rezaei said the Khosravi and Chazabeh crossings had been closed since late Wednesday, but other crossings were open ahead of an annual Shia Muslim pilgrimage in Iraq.

Since erupting in Baghdad on Tuesday, the protests have spread to other cities in the country's south, posing a challenge to Mahdi's one-year-old government.

Anger over staggering rates of youth unemployment, which is around 25 percent or double the adult rate according to the World Bank, appears to have set off the latest round of demonstrations.

"We want jobs and better public services. We've been demanding them for years and the government has never responded," said Abdallah Walid, a 27-year-old protester.

The tension has been exacerbated by a near-total internet shutdown, the closure of government offices and at least one overnight explosion that hit the Green Zone, where some ministries and embassies are located.

A security source inside the area told AFP there were two blasts, likely caused by indirect fire a little over a week after two rockets hit near the US embassy there.

The apparent attack came hours after security forces sealed off the Green Zone "until further notice", fearing angry protesters would swarm state buildings or foreign missions.

The Green Zone had been inaccessible for most Iraqis since the 2003 US-led invasion of Iraq but had reopened to the public in June.

It has often been the focal point for public anger, including in 2016 when al-Sadr's supporters stormed it and paralysed state institutions.