Gun attacks in Baghdad and predominantly Sunni west Iraq on Wednesday left five policemen and a town mayor dead, security and medical officials said.
The violence comes three weeks after US troops completed their withdrawal from Iraq, with the country locked in a political standoff that has raised sectarian tensions.
In Wednesday's deadliest attack, insurgents attacked a police station near the Syrian border early in the morning and killed three policemen, including a captain, according to police and a medic.
Police killed one of the gunmen who carried out the attack in the town of Al-Qaim, in mostly Sunni Anbar province west of Baghdad, and wounded another. A third escaped.
"Three police -- two policemen and a captain -- were killed when several armed men attacked the police station at about 3:00 am (0000 GMT)," said police Captain Mohanned Mukhlif Hamadi.
"The attack was followed by clashes between policemen at the station and the attackers. One of the gunmen was killed and another wounded, but one escaped."
A medic at Ramadi hospital confirmed that the facility had received the body of one of the gunmen and had treated the one who was wounded.
Also in Anbar province, gunmen murdered the mayor of Heet, 170 kilometres (105 miles) west of Baghdad, as he was leaving the mosque, police said.
Saeed Hamdan Ghazal, who had just completed evening prayers, was shot dead by attackers on a motorcycle who then fled the scene, two police officials said.
Ghazal was killed instantly, according to a police spokesman and Iyada al-Nimrawi, the town's deputy police chief.
Anbar province was home to a violent Sunni Arab insurgency in the aftermath of the 2003 US-led invasion that ousted Saddam Hussein, one that only abated after Sunni tribes sided with the US military against Al-Qaeda from late 2006 onwards.
In Baghdad, gunmen armed with silenced pistols killed two policemen in the Baghdad Jadidah (new Baghdad) neighbourhood in the capital's east, officials from the ministries of interior and defence said.
The victims were working in the Iraqi police's anti-terror department and were in an unmarked civilian car, the officials said.
Violence is markedly down from its peak in Iraq in 2006 and 2007, but attacks remain common. 155 people were killed in violence in December, according to official figures.