More than 30 international aid agencies working in the West Bank and Gaza Strip have accused Israel of obstructing their operations to the point that they can no longer fulfil their mandates.

Their joint statement comes as concern mounts about the humanitarian impact of the Israeli-imposed curfews.

On a daily basis we are subjected to excessive delays at military checkpoints, inconsistent and sometimes complete refusal of access and harassment

International agencies' statement

The Israeli army has responded to the criticism by saying that the movement of people and goods has been restricted because of security concerns, but that it is working continuously to help the delivery of aid.

On Wednesday, Israel decided to gradually ease the round-the-clock curfews that have been in force in several West Bank cities since suicide attacks on Israelis last month.

With the Palestinian economy in severe crisis, 32 aid agencies are now appealing to Israel to allow them unrestricted access to a people in growing need.

The agencies have also called on the international community to put pressure on Israel to "ensure humanitarian access is unrestricted as guaranteed under international law".

Restrictions and harassment

The agencies, including Medecins Sans Frontiers, Care International and Oxfam, say their work has been badly undermined by excessive delays at military checkpoints, and harassment and restrictions on the movement of their staff.

As a result, the agencies say, they are often unable to reach people who need basic assistance, as curfews and checkpoints push Palestinians into deepening poverty.

The British aid agency Oxfam says families have been dramatically cutting back on what they eat, and selling off assets to feed themselves.

The World Food Programme is now providing food aid to half a million Palestinians in what it says is the biggest operation in the West Bank and Gaza it has ever mounted.

West Bank re-occupation

An official has said that Israel is in contact with aid agencies and donor countries to ensure relief reaches the Palestinians via Israeli checkpoints rather than through the Palestinian Authority, which the government views as corrupt.

The official, prime ministerial spokesman Ranaan Gissin, did not name the agencies and countries contacted.

Israel has re-occupied large parts of Palestinian-controlled areas of the West Bank, restricting 700,000 Palestinians to their homes except for three or four hours every other day.

Israeli Prime Minister Ariel Sharon has indicated that Israeli forces are going to stay in these areas for an extended period of time to continue operations against alleged militants.

Nablus, Tulkarm, Bethlehem, Ramallah, Qalqilya, Jenin and Hebron were re-occupied following two suicide bombings in Jerusalem that killed more than 30 Israelis.