It was the first death since modest anti-government protests resumed on Sunday, ending months of relative calm just as new Prime Minister Mustafa Kadhemi was sworn in.

Kadhemi has extended a hand to demonstrators and promised accountability for the more than 550 people killed in violence at anti-government rallies that first erupted in October.

Late Sunday, protesters had massed around the office of a local party in Basra, once more demanding the ouster of the Iraqi ruling class they see as corrupt and beholden to Iran.

A 20-year-old protester was shot in the head and later died in hospital, a medical source told AFP.

Hours later, security forces stormed the party office located around one kilometre (less than a mile) from Basra's main protest camp.

"We arrested five men who shot at protesters from the headquarters," Bassem al-Maliky, the press officer for Basra's security forces, told AFP.

They also seized rifles and ammunition from the base.

The arrests marked a rare incident of a swift official response to protest-related deaths, for which only a handful of security forces have been held to account.

Demonstrations meanwhile continued in Baghdad and different parts of Iraq.

In the town of Kut on Monday morning, protesters surrounded the home of the local governor, AFP's correspondents there said.

There were also rallies overnight in Diwaniyah, with hundreds gathering despite advice from authorities to maintain social distancing to curb the spread of COVID-19.

Hassan al-Mayahi, a protester there, said that "despite the dangers of the coronavirus, the political deals of the parties and their neglect of our past demands have forced us to return to the street again to pressure them to give us our rights".