With fear mounting of an impending humanitarian disaster and security worsening, the International Committee of the Red Cross demanded Sunday access to Iraqi prisoners held by US-British coalition forces.

"The ICRC still does not have access to all the prisoners and detainees in the country," said Nana Doumani, the organisation's spokeswoman in Baghdad.

"The parties must respect the Geneva Convention on prisoners," she pleaded.

US Central Command in Qatar announced Saturday that 342 more PoWs had been released, taking the total number set free to 5,745.

Nearly 3,600 Iraqis prisoners remained in detention.

Doumani said about 2,000 people had been arrested for common law offences in the capital since April 10, the day after coalition forces entered and mass looting erupted.

The ICRC has also been denied access to former senior Iraqi officials who have either surrendered or been captured by the coalition forces, including deputy prime minister Tareq Aziz.

The UN chief of mission warned that Iraq is still ripe for a humanitarian disaster even though the shooting has all but stopped, noting that too many people were going without food, water and power.

"The conditions for the development of a humanitarian disaster still exist," Ramiro Lopes da Silva said Saturday.

"It's (already) a humanitarian disaster in the sense basic services have collapsed or are at the risk of collapsing if we don't put them back into shape rather quickly," he said.

Lopes da Silva, who returned to Baghdad on Thursday with other UN

officials who fled two days before the war began on March 20, said nearly two-thirds of Iraqis totally depended on food aid. Malnutrition was rampant.

And the director of British charity Oxfam accused US-led forces of failing to do enough to protect aid workers.

"At the moment it's very high risk for our staff to be in Iraq... that's not good enough," Barbara Stocking told BBC radio on Saturday.

"We need the coalition forces to provide the security, and we need them also to do something about the mines and the unexploded ordnance that there is around.

"The occupying power has to provide the security and they are not. That's their legal obligation under the Geneva Conventions," Stocking said.

Despite the presence of 12,000 US soldiers in Baghad and the planned deployment of up to 4,000 more, security has deteriorated in the city where weapons are easily available and an effective police force has yet to be set up.

In Baghdad's Sadr City, a huge Shiite slum of two million people, hospital officials voice fears for their safety.

"There are large numbers of thieves, drug addicts and accounts are being settled," said Dr Samer Salah al-Khan, noting that "new gangs have appeared."

Several journalists among the hundreds of foreign media in Baghdad have been robbed.

The capital's interim police chief, Zuhair al-Nuaimi, resigned Saturday, saying young blood was need. He urged Iraqis to work closely with US forces.

Meanwhile, several dozen Iraqis staged a rare rally in Baghdad Sunday to thank the United States for removing Saddam Hussein.