The US military says it is now in control of 70% of the Iraqi city of Fallujah and that rebels are confined to a narrow strip of the city.
But Iraqi insurgents claimed they had captured 20 national guards in Fallujah, according to the television station Al-Jazeera, which broadcast a videotape purporting to show the men.
The group, which was not identified, said the men were captured
in Fallujah, and the video showed the men wearing national guard uniform with their backs to the camera.
Eleven US and two Iraqi troops have been reported killed and at least 85 insurgents. There are no indications of civilian casualties.
The commander of the US force, Marine Lieutenant General John Sattler, said insurgents were moving blindly through the streets, unable to communicate with each other as US-led forces pursue them.
US and Iraqi soldiers captured 127 insurgents in a hospital in the city earlier and US marines took the police station and mayor's office on the second full day of the assault on the Iraqi city.
Prime Minister Iyad Allawi has extended the closure of Baghdad's international airport for another 24 hours as part of a series of emergency measures amid escalating violence.
Violence spreads across Iraq
At least five people were killed and 20 injured when a car bomb exploded near a police checkpoint in an eastern district of the Iraqi capital late this evening.
At least nine civilians were killed and 24 injured in fighting in Baiji, 180 km north of Baghdad and there were running battles in the city of Mosul and parts of the capital.
The authorities imposed a curfew on Mosul in northern Iraq today, the fourth city in three days to receive such an order.
Seven people were killed in an earlier bombing in Baghdad. Two roadside bombs just to the north killed six Iraqi national guards and, separately, a US soldier. A policeman was killed and two wounded in a similar attack near Samarra.
Threat to Allawi family members
A militant Islamic group has threatened to kill three relatives of interim Prime Minister Iyad Allawi if the attack on Fallujah does not end within 48 hours.
A first cousin of Mr Allawi, the cousin's wife and another family member were seized from their home in Baghdad yesterday.
A police source said there had been a gun battle at the house before the people were seized.
The kidnappers have also demanded the release of prisoners.
