The blasts were caused by two explosives-laden motorcycles and a roadside bomb and hit three Shiite neighbourhoods of Baghdad. (AFP)

Six people were killed in near-simultaneous blasts across Iraq’s capital late Tuesday, medics and a security source said, amid deadly anti-government protests that have rocked Baghdad and the Shiite-majority south for weeks.

There was no immediate claim of responsibility for the three explosions, which were the first such violence in the capital after months of relative calm.

The blasts were caused by two explosives-laden motorcycles and a roadside bomb and hit three Shiite neighbourhoods of Baghdad, according to medical and security sources.

Around a dozen people were wounded and taken to Baghdad hospitals already treating scores of demonstrators hurt earlier in the day in protests.

Rallies demanding deep-rooted regime change erupted in early October across Baghdad and southern Iraq, leaving more than 350 people dead and around 15,000 wounded.

In the Shiite holy city of Karbala on Tuesday, one person was killed as protests escalated into chaotic “clashes” with security forces, a medical source told AFP.

There were no immediate details about the victim’s identity or cause of death, but the medic said the toll was likely to rise further.

AFP’s correspondent saw riot police fire live rounds both into the air and directly at crowds of teenage protesters with at least one demonstrator suffering a bullet wound to the head.

In one face-off under a bridge, teenagers threw rocks at riot police trucks, bursting into song when the vehicles screeched away.

Clashes also erupted in Baghdad, where security forces fired rubber bullets and tear gas to keep demonstrators away from Al-Ahrar bridge, which leads to government buildings on the west bank of the river Tigris.

One protester died after being shot by a rubber bullet and 18 were wounded, a medical source said.

A body bearing a rubber bullet wound was also found underneath Al-Ahrar on Tuesday, but it was unclear when the person had died, the medic said.

The historic districts near Al-Ahrar have morphed into arenas for daily street battles.

Demonstrators — mostly teenagers who have been there for days or weeks — throw rocks from behind makeshift barricades at security forces firing tear gas, rubber bullets, live rounds and even machine gun fire.

“We won’t leave unless it’s in coffins,” one protester told AFP.

“Either way, I’ve got no job, no money, so whether I stay here or go home, it’s all the same,” said another.

An Iraqi tricolour tied around his shoulders, he went on bitterly: “I’ll never be able to get married without work or a salary, so I’ve got no family and no home anyway.”

Smoke bombs exploded all around the protesters, filling the colonnaded streets with puffs of orange, green and purple.

In the south, protesters burned tyres along highways outside the city of Diwaniyah, blockading bridges and one of the province’s three power stations.

In the city itself, massive crowds marched through the streets, tearing down posters of politicians and beating them with shoes to insult them.

“It’s been two months, we’re sick of your promises,” they chanted.

Schools and public buildings have been shut in Diwaniyah for the past month by strikes and road closures, but skirmishes with riot police have been rare.

In nearby Hillah, usually peaceful sit-ins took a violent turn overnight when security forces fired tear gas grenades at protesters, wounding around 60, medics said.

Demonstrators and security forces in Karbala lobbed Molotov cocktails at each another.

Night-time skirmishes have become routine in the city.

In Dhi Qar, arterial routes linking key cities and the three oilfields of Garraf, Nasiriyah and Subba were shut.

Clashes with police guarding the fields wounded 13 officers.

Together, the three oilfields produce around 200,000 of Iraq’s roughly 3.6 million barrels a day.

Iraq is ranked OPEC’s second-biggest crude producer and, according to Transparency International, the world’s 12th most corrupt country.

The turmoil since the start of October has not significantly impacted oil production or exports, which fund virtually the entire state budget.

Iraq’s cabinet is currently discussing the 2020 budget before it is submitted to parliament, and government sources say it is expected to be one of the largest yet.

That is mostly because of the enormous public sector, which has ballooned in recent years as the government has hired tens of thousands of new graduates in a country with a severely under-developed private sector.

But experts say that model is unsustainable for a country of nearly 40 million people, set to grow by another 10 million in the next decade.

Public anger over a lack of jobs fuelled the latest grassroots protests, Iraq’s most widespread and deadly in decades.

One in five people lives below the poverty line and youth unemployment hovers at a staggering 25 percent, the World Bank says.