FALLUJAH, Iraq (AFP) - The sound of machine-guns and mortars reverberated across the Sunni Muslim bastion of Fallujah as US marines and insurgents battled on despite US efforts to suspend hostilities.
The marines called for women and children to exit the city, but blocked men from leaving as they looked to hunt down those responsible for the brutal murders last week of four US contractors.
Hundreds of fleeing families turned around when the marines refused to let the men leave. Their return to the war zone put a snag in the military's plan to clear Fallujah of civilians before any possible house-to-house fighting.
Intelligence reports said insurgent snipers were taking positions in mosque minarets in the town west of Baghdad where hundreds have been killed in six days of fighting.
"It's going to get worse before it gets better," one marine officer, who asked not to be named, told AFP as the American troops took shelter in the comparative safety of abandoned factories.
Paul Bremer, the US overseer in Iraq (news - web sites), earlier announced a unilateral 24-hour halt in hostilities to enable talks to be held on allowing aid to be moved in to beleaguered residents and for bodies to be buried.
Bremer said the suspension was meant to "allow for a meeting between members of the (US-installed interim) Governing Council, local Muslim leadership and the leadership of anti-coalition forces."
But marine field commanders said the pause was short-lived.
"The suspension of offensive operations lasted for 90 minutes but it is over," said Lieutenant Colonel Brennan Byrne, a battalion commander, adding that planned talks with local tribal sheikhs never came off.
Major Pete Farnum said: "We went into pause but the enemy kept attacking us on the western side of the city. We had to defend ourselves so we asked for permission to return to offensive operation. This was granted."
There was no further word from Bremer or the coalition's deputy director of military operations, Brigadier General Mark Kimmitt, who had earlier insisted the suspension of offensive operations was still in force.
But as night fell in troubled Fallujah, Byrne made clear he had received no new orders to halt the campaign.
"Right now, we're going back to the attack. My colonel told me we're still on the offensive."
Sporadic US machine-gun fire echoed through the town as did the explosion of rocket-propelled-grenades (RPGs) and mortar rounds fired by insurgents, but the fighting was less intense than in previous days.
Later at night more explosions could be heard as US aircraft buzzed the sky. Marine officers said AC-130 gunships were firing heavy ammunition, but it could not be independently confirmed.
More than 400 Iraqis have been killed and 1,000 wounded in the US offensive launched Monday, an aide to a Governing Council member said in Baghdad.
"These numbers were given to us from Fallujah, from all hospitals, and they are correct 100 percent," said Hatem al-Husseini, an aide to council member Muhsin Abdul Hameed from the Iraqi Islamic Party.
The US military also said at least two marines were killed.
The US troops were holed up in abandoned, rat-infested factories edging the residential sector of the town, some 50 kilometres (30 miles) west of Baghdad. They were gearing up for a bruising fight.
"The word has passed from on high that snipers are hiding in minarets from noon today because they know we can't engage a mosque unless they engage us first," said one marine officer, who asked not to be named.
"They are trying to trap us with the rules we follow ... They blanket themselves in the grey area of war," the officer said.
In the squalid streets between the US troops and insurgents, bodies remained where they fell, with relatives too afraid to recover them for burial.
Marines said they saw a dog pulling at one body which had been in the sun for at least 24 hours.
Before the US unilateral suspension was announced, one marine was wounded in a clash with insurgents on the edge of the industrial area. The marines said he was hit by an RPG in the southeastern sector which was believed to be secure.
Around 11:30 am (0730 GMT), a tank opened fire on enemy positions. One of six shells punched a hole in the minaret of a mosque that had been bombed on Wednesday. One marine officer said a sniper was in the yellow minaret.
The marines said that rules of engagement had been eased to allow the readier use of tanks and artillery.
One lieutenant, speaking on condition of anonymity, said: "Basically the situation has escalated since we rode into Fallujah. At first, the plan was to shake hands with the people and engage the enemy where we find him. But when we came in here, all we faced was the enemy."
Food supplies were running short in the besieged town and Thursday residents were invited to get handouts from Sunni clerics at hospital and morgues after a food convoy managed to enter the town, an AFP correspondent reported.
Marines later allowed more than 20 trucks of aid to enter, with some of the supplies distributed at a designated gathering point, officers said.