The US military said it had killed eight guerrillas on Saturday, and rejected allegations by local doctors that civilians had also been killed in US air strikes.
They also rejected an al-Qaeda claim on Sunday to be holding two US marines hostage in western Iraq as Marines attacked al-Qaeda guerrillas in the region for a second day.
A statement on a site used by the group said: "Al-Qaeda soldiers succeeded in kidnapping two marines ... Al-Qaeda gives the infidels 24 hours to release female Sunni Muslim prisoners ... or they should not bother to look for their children."
But a US military spokesman in Baghdad, Lieutenant Colonel Steve Boylan, said: "I have not heard anything about any of our folks being taken. I would suspect that these are unfounded rumours, as that is what has happened in the past."
"There are no indications that al-Qaeda claims of having kidnapped two Marines in western Iraq are true," Marines spokesman Major Neil Murphy said in a statement.
"Multi-National Force West is conducting checks to verify all Marines are accounted for," he added.
It was not immediately possible to verify the authenticity of the Web statement, which was signed with a name that usually accompanies the group's official announcements.
It said the Marines had been captured during "Operation Iron Fist", the latest of many recent offensives by about 1,000 US troops against al-Qaeda around Qaim on the Syrian border.
Meanwhile, Interior Minister Bayan Jabor told Reuters that documents seized after troops killed a purported aide to al-Qaeda's leader in Iraq, the Jordanian Abu Musab al-Zarqawi, indicated a plan to spread violence to other Arab countries.
"We got hold of a very important letter from Abu Azzam to Zarqawi asking him to begin to move a number of Arab fighters to the countries they came from, to transfer their experience in car bombings in Iraq," he said in an interview in Amman.
"So you will see insurgencies in other countries," said Jabor.
Jabor lashed out at Iraq's fellow US ally, Saudi Arabia, for saying Iraq could break up along sectarian and ethnic lines, fuelling wider regional conflict.
Telling Saudi Arabia to mind its own business, Jabor added: "We as Iraqis are responsible for solving our own problems."
He was speaking a day after his brother, a doctor, was kidnapped and later freed by gunmen in Baghdad.