Three other people were wounded in the incident, Karim Shuak, a member of Basra's provincial council, told AFP.

He said the demonstrators were "youths demanding solutions to the problem of unemployment that has deteriorated because of the inaction of the federal government".

Hussam Abulhil, a head of the Bani Mansour tribe to which the slain 30-year-old protester belonged, said demonstrators wanted his killer to face justice and the dismissal of Basra's security operations chief.

The protests, like Tuesday's in front of the local government offices, will carry on, he said, while the interior ministry, for its part, said an investigation would be opened.

Officially, unemployment in Iraq, where the under-24s represent six out of 10 of the population, is running at 10.8 percent.