Iraqi security forces fired live rounds on Monday at anti-government protesters in Baghdad, hours after four demonstrators were shot dead outside the Iranian consulate in the holy city of Karbala.

It was the latest bloodshed in a wave of ongoing protests, roadblocks and a campaign of civil disobedience waged by protesters accusing the Iraqi government of rampant corruption and clientelism.

Activists also hurled stones at security forces firing tear gas grenades in clashes on the capital's streets leading to the Iranian embassy, the seat of government and the foreign and justice ministries, an AFP photographer reported.

About 20 people were wounded in Baghdad, medical and security sources said, when security forces opened fire on protesters massing near the state television headquarters, according to witnesses.

It was the first time live ammunition was fired at Baghdad demonstrators, since protests resumed on October 24, following a period in which riot police had switched to use tear gas amid accusations of "excessive force."

Some 270 people have died since the anti-government rallies broke out on October 1, according to an AFP count, but officials have stopped providing precise casualty numbers.

Internet access in the capital Baghdad and much of Iraq has been cut off, reported the internet blockage observatory late on Monday.

"At the time of writing, national connectivity has fallen below 19 percent of normal levels sending tens of millions of users offline across Baghdad, also impacting Basra, Karbala, and other population centers. The new disruption is believed to be the most severe observed in Iraq to date," NetBlocks said in a statement.

"Intent to kill"

Overnight, a crowd of protesters gathered in Karbala, about 100 kilometers south of Baghdad, at the consulate of neighboring Iran, which they accuse of propping up the government they are trying to overthrow.

They scaled the blast walls and aimed fireworks at the building and, as the crowd grew, heavy gunfire and volleys of tear gas rang out.

"They intend to kill, not disperse," said one young protester about Iraqi forces guarding the mission.

The forensic medicine department later confirmed four protesters died after being shot.

"My son went out to protest with the rest of the young Iraqi men and got shot once in the shoulder and a second time in the head. He was 20," said Wissam Shaker.

Another relative of a casualty, who declined to give his name, said the protesters had been unarmed.

"If the governor comes out and says these protesters had grenades or weapons, he's lying! They had nothing but stones while security forces fired bullets," he said.

(With input from agencies)