Hansen harshly criticised the Israeli government for creating widespread destruction in civilian areas during their incursions and for obstructing UNRWA workers attempting to access areas in the West Bank and Gaza. About 50 per cent of the population now live below the poverty line, he said.

'The situation is extremely severe,' Hansen said. 'Gaza and the West Bank are not accessible and food stocks are running low. The hardest hit are the areas under occupation and curfew. In Rafah a whole segment of a camp was flattened, bulldozed and then covered in sand. We are now preparing to set up shelter for the refugees.'

Hansen also accused the Israeli authorities of little or no co-operation with aid agencies trying to provide basic relief. 'We were only able to access some of the camps for a few hours,' Hansen said. 'There is a humanitarian crisis going on. Clinics are destroyed, people cannot move around and provide urgently need medicine, food and water.'

Hansen said that UNRWA is 'very dependent' on Israel. 'We can only access the Palestinian areas with Israel's permission. They are creating huge bureaucratic obstacles for us.'

Hansen said that the agency would need free access to roll out its emergency aid and to treat the injured in mobile clinics.

With the crisis in the Palestinian areas deepening, UNRWA in April appealed to donor nations to pay their annual contributions to the agency, which has received less than 40 per cent of the anticipated $117 million for 2002.

'This figure was calculated in the beginning of 2002, based on an earlier situation, but it will now significantly increase,' Hansen said. 'We hope that we can get the funding for our regular programme, which aims to support the poorest of the poor. But we also need funding for our emergency programme, which will allow for rebuilding destroyed homes, help the wounded and other urgent measures.'

UNRWA workers on 16 April announced that they had received permission to enter Jenin camp to supply two truck loads of foods and medicines. The aid workers described the destruction as looking like the aftermath of an earthquake, with people still trapped under collapsed buildings.