Militants attacked a police station in north Iraq on Wednesday with mortar rounds and automatic weapons, killing nine police, doctors and officials said.
The violence comes a day after an Al-Qaeda front group claimed brazen assaults on two prisons in Iraq that killed more than 40 people, among them 20 security forces members, and saw hundreds of inmates, including senior militants, escape.
Security forces are desperately hunting the prisoners who escaped in Sunday night's jailbreaks to prevent them rejoining the ranks of the militants and carrying out further attacks.
Wednesday's assault on a police station about 60 kilometres (37 miles) south of the northern city of Mosul, also left two policemen wounded, the sources said.
It was followed by a roadside bomb explosion as emergency personnel travelled to the scene, wounding another two people.
In a separate incident, gunmen killed a man in Baquba, a city north of Baghdad.
Iraq has faced years of attacks by militants, but analysts say widespread discontent among members of its Sunni Arab minority, which the government has failed to address, has fuelled the surge in unrest this year.
Iraqi security forces are frequently targeted by militants opposed to the government in Baghdad.
With the latest unrest, more than 650 people have been killed so far in July, making it the deadliest month in a year marked by spiralling violence.
Iraq's Sunni Arabs accuse the Shiite-led government of marginalising and targeting their community, including through unwarranted arrests and terrorism charges.
Protests broke out in Sunni-majority areas at the end of 2012 and are still ongoing.
In addition to the major problems with security, the government in Baghdad is also failing to provide adequate basic services such as electricity and clean water, while corruption is widespread.
Political squabbling has further paralysed the government, which has passed almost no major legislation in years.