Iraqi police wielded batons and rubber hoses to disperse about 250 protesters gathered at the main entrance to the Zubair oilfield near Basra on Tuesday as unrest across southern cities over poor basic services gathered pace.
Since demonstrations began nine days ago, protesters have attacked government buildings, branches of political parties and powerful Shiite militias and stormed the international airport in the holy city of Najaf.
Tensions focused attention on the performance of Prime Minister Haider al-Abadi, who is seeking a second term after May 12 parliamentary elections tainted by allegations of fraud that prompted a recount.