At least five Iraqis were killed when militiamen loyal to radical Shi'ite cleric Moqtada al-Sadr attacked a US base near the holy city of Najaf, south of Baghdad.
Journalists on the scene report gunfire and at least 20 mortar rounds hit in and around the base today, Monday. US forces returned fire.
No US casualties have been reported, but local officials say 16 people were wounded in the clash.
Mr. al-Sadr's militiamen tried to instigate an uprising last month across parts of southern and central Iraq.
Meanwhile, in the volatile city of Fallujah, news reports say U-S generals are likely to name General Mohammed Latif, who served in Saddam Hussein's army, to head the new Iraqi security force there.
In another development, the US military says American soldiers fired mortar rounds at insurgents in western Baghdad, killing four. A military spokesman reported no casualties on the American side.
Also, south of Baghdad, one US soldier was killed and two others wounded on Monday when they were attacked with small arms fire. Another soldier was killed in al-Anbar province, west of Baghdad.
Meanwhile, the Canadian Foreign Ministry has confirmed that a dual Iraqi-Canadian citizen was abducted last week in Baghdad. There is no word on who abducted Naji al-Kuwaiti or why.