Suicide bombers killed four people in north Iraq on Wednesday, while seven more people, among them a gunmen, died in other violence, officials said.

One suicide bomber driving an explosives-rigged car targeted security forces from Iraq's autonomous Kurdistan region, known as peshmerga, near the northern city of Kirkuk, killing a peshmerga and wounding 12, police and a medical official said.

Another suicide car bombing at an office of President Jalal Talabani's party in Kirkuk killed one person and wounded 38, officials said.

And in Tuz Khurmatu, a town in Salaheddin province, a suicide car bomber attacked a peshmerga checkpoint, killing another peshmerga member and wounding another, officials said.

Both Kirkuk province and Tuz Khurmatu are part of a swathe of north Iraq territory that Kurdistan wants to incorporate into its autonomous region over the strong objections of the federal government in Baghdad -- a dispute diplomats and officials say is a major threat to Iraq's long-term stability.

Another suicide bomber struck in the northern city of Mosul, killing one person and wounding four, including a policeman, police and a doctor said.

In Fallujah, west of Baghdad, gunmen opened fire on a police checkpoint, killing three police and wounding two others, police and a doctor said. One gunman was also killed in the attack.

Gunmen armed with silenced weapons killed a taxi driver in the Jamiyah area of west Baghdad, while a roadside bomb wounded three people in the capital's north and a magnetic "sticky bomb" on a vehicle killed two people and wounded five near the capital, officials said.

Violence in Iraq has fallen from its peak at the height of the sectarian conflict in 2006 and 2007, but attacks remain common and have killed more than 200 people in each of the first four months of this year.

With the latest unrest, 82 people have been killed in violence in Iraq so far this month, almost half of them members of the security forces, according to AFP figures based on security and medical sources.