KIRKUK, Iraq - Assailants raked a checkpoint with bullets, killing a policeman and a civilian west of the northern city of Kirkuk on Wednesday, amid further violence in war-torn Iraq.
US troops arrested more than 80 people in hotbeds of anti-US resistance, where a shadowy and loose alliance of former Baath party loyalists, Islamic militants, foreign fighters and criminals have caused mayhem in the post-Saddam Hussein era.
In the latest attack on Iraqi police, a checkpoint was ambushed on the road between the northern oil refinery of Baiji and the town of Hawijah, 80 kilometres (50 miles) northeast of Kirkuk.
"Unknown gunmen sprayed automatic weapon fire at a police checkpoint ... killing a policeman and one civilian," said police officer Ahmad Hassan Ali.
The civilian's car was stopped at the checkpoint when the gunfire erupted at 7:10 am (0410 GMT), the officer said.
The attackers immediately fled.
A policeman was also killed on his way to work near the northeastern city of Baquba on Tuesday.
Since a wave of suicide car bombings kicked off in August, Iraqi security forces have established checkpoints on the highways to search for suspect individuals.
Meanwhile, US forces raided suspected resistance strongholds in jailed leader Saddam's home region north of Baghdad.
The 4th Infantry Division-led Taskforce Ironhorse, which patrols the provinces of Tamim, Salahuddin and Diyala, seized 53 people from Monday to Tuesday, the military said.
In the flashpoint province of Al-Anbar, the 82nd Airborne and 3rd Armored Cavalry Regiment detained "27 enemy personnel" over a 24-hour period ending Tuesday, the military said.
Three insurgents were captured after a firefight in Khalidiyah, a town on the outskirts of Fallujah, 55 kilometres (nearly 35 miles) west of Baghdad.
US soldiers returned fire from a three-storey house before capturing the three guerrillas, the statement said.
Meanwhile The US-led coalition will release 100 people from Iraqi prisons on Thursday, with hundreds more to be freed in coming weeks, the top US official in Iraq Paul Bremer was to announce in a policy address later Wednesday.
Bremer, with current interim Governing Council president Adnan Pachachi at his side, was also to unveil a 200,000-dollar reward program for the capture of more wanted individuals, according to an advance copy of his speech.
The release programme is aimed at bringing a new bounty of intelligence from those Iraqis being freed under the new policy, a coalition spokesman said.
"We're hoping these people will take this opportunity to help the new Iraq by giving information on those who are going out killing and hurting people," the spokesman said.
"Tomorrow, the coalition will release at least 100 persons now detained by the coalition," according to Bremer's address. "Hundreds more detainees will be freed in this way in the coming weeks."
Those released will be set free on the understanding they "must renounce violence" and have "a guarantor, such as a prominent person in his community or a religious or tribal leader, who will accept responsibility for the good conduct of the individual who is being set free."
Bremer's statement describes those being let out as not directly linked to violence against US forces.
"Let me reassure you that this is not a program for those with blood-stained hands. No person directly involved in the death or serious bodily harm to any human being will be released," the statement reads.
At least 10,000 people are currently detained by the coalition, of whom nearly 4,000 belong to the Iranian armed opposition group, the People's Mujahedeen.