Six mortars were fired at about 11:20 pm (2020 GMT) on central neighbourhoods in Kirkuk, 225km (140 miles) north of Baghdad, said Lieutenant Colonel Turhan Yusuf, head of police forces in Kirkuk.
Aidan Izz al-din, 54, was killed instantly when a mortar slammed into his house, close to a US position, while eight other civilians were wounded, including two who are in a serious condition, when a second mortar hit another house near a UN office.
The four other mortars fell near a police station, two bridges and Hotel Baba Gargar, which usually houses Turkish business people, without inflicting damage, he said.
Tensions have been running high in Iraq which has objected to US-backed Turkish plans to dispatch peacekeepers to Iraq, fearing military involvement by neighbouring countries might interfere with domestic politics.
Oil-rich Kirkuk has also become an active front in the war between the US military and insurgents since the 9 April fall of president Saddam Hussein, with attacks mostly targeting US bases and oil pipelines.
The mortar attacks came at the end of one of the worst days for the occupying forces with at least 18 US soldiers killed in sevaral attacks.