US warplanes and artillery units fired on the insurgent-held city of Fallujah overnight, killing four people and wounding six, hospital officials said.
An artillery barrage on an industrial area in Fallujah early today left two people dead and two others wounded, said Dr Ahmed Khalil of Fallujah General Hospital.
The US military said tanks opened fire on suspected militants using a crane, a tractor trailer and other heavy equipment to build fortified positions in an area previously used to mount attacks on Marines deployed on the city's outskirts.
Late last night US warplanes fired missiles on a main street in the city centre, killing two people and wounding four, said another hospital official, Dr Rafea Heyad.
The US military had no immediate comment about the attacks on the industrial zone, but said Saturday's strikes hit a checkpoint manned by insurgents linked to alleged terror mastermind Abu Musab al-Zarqawi.
"The illegal checkpoint used blockades to disrupt security, intimidate and harass local citizens and interrogate and detain local civilians," the military said in a statement.
The attacks were the latest in a series of strikes in and around Fallujah since late on Thursday.
Al-Zarqawi's Tawhid and Jihad group claimed responsibility for a series of deadly attacks in Baghdad during the past week as well as a number of car bombings, kidnappings and other assaults meant to destabilise the US-backed interim authorities.
American troops have not entered Fallujah since ending a three-week siege of the city in April that left hundreds dead.