At least one man was killed and another wounded overnight as police and protesters clashed in Iraq's ethnically split oil city of Kirkuk, police said.
The city, 250 km (155 miles) north of Baghdad, was the site of fierce protests earlier this week over a political bid by Kurds for control of the city that resulted in several deaths.
The protests are the latest episode of violence among Kurds, Arabs and Turkish-speaking Turkmen in the city as they vie for political power after the fall of Saddam Hussein, who had driven Kurds and Turkmen from Kirkuk.
At least five people were killed on Wednesday when gunfire erupted as Turkmen and Arabs faced off with the mainly Kurdish police during a protest against a plan to include Kirkuk in a Kurdish administrative unit in a federal government.
Kirkuk police commander Shirko Shakir said a similar protest late on Friday led to an exchange of gunfire with police, who detained a wounded Arab gunman. Another man, whose ethnicity Shakir declined to specify, was found killed in the area where the protest and clashes occurred, he said.
"From the amount of shooting we assume that there are more wounded and killed whose bodies they took away, and we are watching hospitals and private doctors for them," he told Reuters, blaming the violence on provocateurs loyal to Saddam.
Traffic flowed normally through the streets of the city, which sits on Iraq's richest oil reserves, and shops opened for business as worshippers left mosques after Friday prayers.