"Saif Abu Mishaal Hasan, in charge of the Iraqi National Accord (INA) in Salah al-Din, was kidnapped from his house in Dijla" near Samarra, 120km from Baghdad, the sources said on Thursday.
Armed and masked men in four cars snatched Hasan late on Wednesday. The INA, Allawi's party, says that more than 20 of its members have been killed this year and over 40 since the fall of Saddam Hussein's regime in April 2003.
Last month, the group led by Iraq's most wanted man, Abu Musab al-Zarqawi, released a film showing the killing of an INA candidate for the 30 January elections.
Elsewhere, a bomb targeting a police patrol in Samarra killed a police officer and wounded four others on Thursday, a police officer said.
And three police officers and a fighter were killed in an assassination attempt on a police captain late on Wednesday near Samarra.
Anti-US fighters have killed a
number of foreign workers
"The unknown man opened fire on my convoy, police returned fire and three of them were killed in the ensuing firefight, as well as the attacker," Captain Mudir al-Baldawi said.
Iraqi and US forces arrested former ruling Baath Party member Malik al-Hmud at his home in the same area on Wednesday night, police said, adding that he was accused of helping the fighters.
Turk found dead
Meanwhile, a Turkish national is thought to be among eight people found shot dead north of Baghdad, Iraqi police said on Thursday, adding that all the victims were employed at a US military base.
Initial reports after the corpses were found near the town of Balad on Wednesday had indicated that four foreigners might be among the victims.
"Seven of the dead are Iraqis but the eighth is believed to be a Turk as he has the name 'Turkey' tattooed on his body"
Adil Abd Allah,
Balad police officer
"Seven of the dead are Iraqis but the eighth is believed to be a Turk as he has the name 'Turkey' tattooed on his body, but none of them were carrying identification papers," Balad police officer Adil Abd Allah said.
He said the eight were captured as they were heading to work on a US base some 10km from Balad.
A police officer who was a member of the patrol that discovered the bodies, said most of the victims had their hands tied behind their backs. They had all been shot and one of them also had his throat slit, police said.
Dr Muhammad Jaafar of Balad hospital said the victims had been dead for at least three days when they were found.
Separately, two US soldiers were killed in a vehicle accident in southern Iraq, the US military said on Thursday.
"Two soldiers assigned to the First Marine Expeditionary Force were killed in a non-hostile vehicle accident yesterday (Wednesday), while conducting security and stability operations in the northern Babil province," said a statement.
Four other US soldiers died in Iraq on Wednesday, including three in non-hostile incidents.