This article is more than 10 months old

This article is more than 10 months old

Masked gunmen have opened fire on Iraqi protesters in the Shia holy city of Karbala, killing at least 18 people and wounding hundreds, security officials said, in one of the deadliest single attacks on protesters since anti-government demonstrations erupted earlier this month.

The attack, which happened overnight, came as Iraqis took to the streets for a fifth consecutive day, protesting against corruption, lack of services and other grievances.

The bloodshed in Karbala, a major pilgrimage site where a revered Shia figure was killed in a seventh-century battle, could mark a turning point in the demonstrations in which 240 people have been killed so far this month.

It was not immediately clear who was behind the attack, and protesters said they did not know whether the masked men were riot police, special forces or Iran-linked militias. The protesters said Iraqi soldiers had been stationed around the protest site but withdrew after the attackers began firing teargas and live fire.

Amid a clampdown by security forces, it was difficult to piece together what exactly prompted the attack. There were differing accounts and death toll estimates.

The provincial governor, Nassif al-Khattabi, denied that any protesters were killed but said there were some injuries among security forces.

He said videos that had spread online were fabricated and not from Karbala. Footage purporting to show the aftermath of the attack showed fires and people running away to the backdrop of heavy gunfire. His description contradicted that of people who were at the scene.

An AP video showed a night-time fire and young protesters, some of them taking cellphone footage, as gunfire echoes in the background. An ambulance can be seen trying to drive amid the chaos, and Iraqi security forces arriving at the scene.

The protests across Iraq, leaderless and largely spontaneous, have been met with bullets and teargas by security forces.

At least 73 protesters – not including the latest fatalities in Karbala – have been killed since anti-government demonstrations resumed on Friday, after 149 were killed during an earlier wave of protests this month.

Tuesday’s attack happened in Karbala’s Education Square, where protesters had set up tents.

“We saw masked men dressed all in black and they fired live bullets toward the square,” one demonstrator said. “People fell dead and wounded right next to me. We tried to escape but when we fled into the alleys we ran into moving checkpoints set up by these forces. They arrested people and searched their phones for video of what had happened.”

Another witness said hundreds of protesters were in the encampment when someone opened fire from a passing car. Masked gunmen in black plainclothes arrived and started shooting at the protesters.

Iraqi security officials confirmed the death toll, speaking on condition of anonymity because they were not authorised to talk to reporters.

Karbala, along with Baghdad and cities across southern Iraq, has been gripped by a wave of anti-government protests that have often turned violent, with security forces opening fire and demonstrators torching government buildings and headquarters of Iran-backed militias.

The demonstrations have erupted in Shia-majority areas and have been directed at the Shia-dominated government and Shia political parties and militias, many of which are supported by neighbouring Iran.

The demonstrations are fuelled by anger at corruption, economic stagnation and poor public services. Despite its vast oil wealth, Iraq suffers from high unemployment and crumbling infrastructure, with frequent power outages that force many to rely on private generators. The protests have grown and demonstrators are now calling for sweeping changes, not only the government’s resignation.