UN Secretary General Kofi Annan has said US raids on insurgents are worsening the situation in Iraq and he called for negotiations to help calm the situation.
He was speaking as US helicopter gunships pounded suspected insurgent positions in Fallujah for a second day today.
Despite the attacks, US commanders said they were still committed to ongoing peace talks.
Helicopters and planes rained missile and machine-gun fire
on to buildings after heavy battles broke out in the north of the city.
Plumes of black smoke could be seen rising as the helicopters made repeated raids and snipers fired high-velocity rifle rounds at targets in the apparently deserted streets.
Overnight, US forces carried out one of the heaviest attacks on Fallujah since the siege began three weeks ago.
Two soldiers were killed and a third wounded in a rocket-propelled grenade attack on their patrol in Al-Suwaira, south of Baghdad.
It is not yet clear if this includes the Ukrainian soldier killed when his patrol was attacked south of Kut.
Another soldier has died of his injuries in northern Iraq.
Hundreds killed in recent weeks
Hundreds of people are thought to have been killed in recent weeks in fighting between insurgents and coalition forces.
In a separate development, the United Nations Special Envoy to Iraq, Lakhdar Brahimi, has said an interim Iraqi government could be chosen by the end of this month, despite what he called the extremely worrying security situation in Fallujah and elsewhere.
However, he proposed the establishment of a caretaker government by the deadline of 30 June, whose members would be chosen by the Iraqis.
Mr Brahimi was briefing the UN Security Council in New York.
