As the war in Iraq entered its second week, humanitarian workers were expressing frustration about the lack of aid getting into the country.
With the withdrawal of UN staff from Iraq on the eve of war, it is very hard for the agencies to get an accurate picture of what is going on, but immediate concerns include:
Food
The UN says the majority of Iraqis are likely to exhaust their food reserves by May. It plans to support a food distribution system capable of meeting the needs of the entire population, some 27.1 million people.
The World Food Programme has only 30,000 tons of food stockpiled - enough to feed about two million people for a month. It says it needs 460,000 tons a month to feed the population if the UN-administered oil-for-food programme is not restarted soon.
The UN Security Council voted unanimously on Friday that the programme, which was suspended on the eve of the war with Iraq, should be revived.
Basra
The immediate concern is the lack of clean water, after power to the main water treatment centre was knocked out last week. There are reports that people have been drinking from putrid rivers, raising the spectre of an outbreak of disease.
The International Committee of the Red Cross has been repairing the facility and on Friday said it was working at just over half capacity.
But, while half of Basra's 1.2 million inhabitants now have access to drinking water, three urban centres south of the city remain disconnected, the Office of the UN Humanitarian Coordinator for Iraq (UNHCI) said. About 400,000 people are affected and remain at risk, with repair work impossible under present conditions, it added.
Battles have been raging around Basra and UK military officials accuse Iraqi forces of firing on civilians trying to leave the city.
Aid operations at Umm Qasr
Aid agencies are lining up dozens of vessels to take humanitarian relief into Iraq, but they are being held up because of the security situation in the south.
A ship carrying more than 200 tonnes of emergency supplies, including food, water, blankets and medical kits, docked at Umm Qasr on Friday - but aid workers said it was a "drop in the ocean" compared to what was needed.
Northern Iraq/ Kurdish controlled area
Tens of thousands of civilians have fled north to the mountains and countryside away from towns and cities close to the border with Iraq and the Kurdish autonomous region.
Most have gone to stay with family but many, according to aid agency Save the Children, have been seeking shelter and are in urgent need of fuel, food and clothing.
The agency says it is providing shelter to more than 1,300 families in schools in the north.
Civilian casualties
Civilians have been caught up in the intense fighting in and around cities and towns in the south and the capital, Baghdad, has been pounded by coalition planes for more than a week.
It is impossible to know the figures of civilian casualties but aid workers are concerned about an acute shortage of medical supplies.
The World Health Organisation says access to civilians caught up in the conflict is urgent and has asked the warring parties to consider setting up a humanitarian corridor, or allow pauses in the fighting in order to let aid workers through.