Iraqi Prime Minister Ibrahim Jaafari has said an offensive in the town of Talafar will continue until all the insurgents there have been eliminated.
More than 80% of Talafar's residents are believed to have fled
Mr Jaafari said insurgents and foreign fighters had been actively destroying life in the town.
US forces have carried out bombing raids overnight on Thursday on the town, near Syria.
The Americans say the town is being used as a staging post by foreign fighters crossing into Iraq from Syria.
"Iraqi security and coalition forces continue to eliminate terrorists and foreign fighters in Talafar and they will continue to pursue this endeavour to the end," Mr Jaafari said.
"We are taking additional measures to ensure security and stability in Talafar and to restore its people's rights."
Baghdad airport closed
In a separate development, the international airport in the capital, Baghdad, was closed on Friday.
The British company providing security suspended operations because of a dispute over payment with Iraq's Ministry of Transport.
A statement by the company, London-based Global Strategies Group, said the ministry "is not currently paying the company for the services it has rendered".
No payment had been received for the last seven months, the statement said.
The company said its staff would continue to secure the airport, but that normal airport operations would be suspended until further notice.
The Ministry of Transport owns the sprawling airport complex 18km (12 miles) from central Baghdad.
Iraqi officials say the firm is demanding too much money for security, and, if necessary, Iraqi soldiers will replace the private security guards.
The airport was last closed for the same reason in June. It reopened two days later.
In Talafar, air strikes were reportedly launched on a neighbourhood the Americans suspected of being under the control of insurgents.
Troops were then sent in to arrest all males over the age of 20 who remained there.
The town has been the scene of heavy fighting over the past week, and the authorities have urged residents to leave.
The BBC's Jon Brain in Baghdad says 80% of the town's inhabitants, who are mainly Sunni Muslims, are now believed to have left Talafar.
The US military drove the insurgents out of Talafar a year ago, only for them to return once the troops had withdrawn.
The spokesman for the American forces in Iraq, Major General Rick Lynch, has pledged that this time a sufficient military presence will remain to prevent the same thing happening again.
Also on Friday, Iraqi police said they had found six unidentified bodies in Rustamiyah, about 20km (12 miles) south of Baghdad. They said the men had been tied up and shot, before being dumped in the sewage system.