US challenges Falluja militants

Falluja has been at the heart of the anti-US insurgency

US forces besieging the Iraqi city of Falluja have issued an ultimatum to Sunni militants, urging them to give up their arms or face fresh fighting.

Spokesman Gen Mark Kimmitt told the BBC that offensive operations would resume unless heavy weapons were surrendered.

He was speaking after the US-led coalition announced measures to end the military stand-off there.

These include shortening the curfew and allowing unfettered humanitarian access to the people of Falluja.

Residents of Falluja contacted on Tuesday morning by Reuters news agency said there had been no fighting since the measures were announced on Monday.

The agency also reported that civilians who had fled the fighting in the city were now trickling back - but were forced to do so on foot, as US marine checkpoints had turned back vehicles.

Speaking to the BBC World Service's World Today programme, Gen Kimmitt said the US did not know how many heavy weapons the Sunni militants had, but insisted that the "overwhelming majority" must be handed in.

He gave no timetable, but said the aim was to bring Falluja under coalition control.

Gen Kimmitt also sought to play down reports of heavy civilian casualties in Falluja over the past two weeks, saying the reports needed to be verified by the Iraqi government.

He also appeared to acknowledge that no direct talks had been held with the actual militants who, he said, included foreign fighters.

Fragile truce

The Falluja agreement came after days of talks between senior US officials and representatives of local Iraqis.

Dan Senor, the US administration's chief spokesman, said the deal included:

• Better access to local hospitals so the wounded could be treated, as well as for retrieving and burying bodies

• Amnesty for people who hand in their weapons

• Easy access for ambulances

• Shortening the curfew by two hours

• Regular joint patrols between US forces and local Iraqis

• Reforming police and the Iraqi defence corps - which will be able to take over and pledge to eliminate "foreign fighters, criminals and drug users in Falluja", said Mr Senor.

It is not clear whether the Iraqi civic leaders taking part in the negotiations are able to control the insurgents.

They have said they do not control about 20% of the population of the city, says the BBC's Dominic Hughes in Baghdad, and the support of this percentage could be crucial to the future of the deal.

The US offensive started early this month following the killing and mutilation of four US security contractors in Falluja.

Hundreds of civilians are reported to have been killed in the fighting.

An uneasy ceasefire has been in force for more than a week.

Militants in Falluja - in the area known as the Sunni triangle - have spearheaded the Iraqi insurgency against the US-led occupation of Iraq, which has now spread south of Baghdad to include Shia militants loyal to radical cleric Moqtada Sadr.

The US-led coalition has also been involved in negotiations to resolve a stand-off in the holy city of Najaf with militias loyal to Mr Sadr.