Ahmad Abdessamad, a 37-year-old correspondent for local television station Al-Dijla, and his cameraman Safaa Ghali, 26, were killed late Friday, the Journalistic Freedoms Observatory (JFO) said.

Hundreds marched through the streets of Basra carrying symbolic coffins, their pictures and Iraqi flags.

One mourner told AFP: "What happened was an attempt to scare people. But now, everyone in Basra has come out to mourn Ahmad and his colleague Safaa. It was clearly an attempt to silence people."

The two reporters were in a car near a police station in Basra when armed men in a 4x4 approached them and opened fire.

"Armed men attacked them and sprayed them with bullets on Friday night, which killed Abdessamad. His cameraman was taken to the city hospital, where he died," the JFO said in a statement.

It said that two weeks before he died, Abdessamad had sent the JFO video testimony about "threats he received from militias because of his criticism of Iran in his coverage."

Demonstrations erupted in October in Iraq's capital and across its Shiite-majority south, railing against government graft and a lack of jobs.

The protests have also slammed neighbouring Iran for economic and political overreach in Iraq and for propping up a ruling class reviled by demonstrators.

As the protests drag on, activists have complained of a growing campaign of intimidation, including assassinations, kidnappings and threats, meant to keep them from the rallies.

Around a dozen activists have been shot dead and are among the more than 460 people killed in protest-related violence since October.

The rallies had been overshadowed in recent weeks by rising tensions between the US and Iran but protesters revived them on Friday, including in Basra, where some demonstrators were arrested.

The Iraqi Journalists' Union demanded Basra's police conclude a speedy investigation so that "the criminals be brought to justice".

The Committee to Protect Journalists, meanwhile, condemned the killing and urged Iraqi authorities to do more to protect reporters covering the movement.

"No journalist should have to fear for their safety or be singled out for attack over their coverage of protests," said the CPJ's regional representative Ignacio Miguel Delgado.