Ramallah, Occupied West Bank - A year and a half after Israel's last war on Gaza, the humanitarian crisis continues to grow in the strip as a result of water contamination, energy shortages and a stagnant unemployment rate, according to the United Nations.

On Wednesday, the UN Office for the Co-ordination of Humanitarian Affairs in the Occupied Palestinian Territories (OCHA-oPT) launched an appeal, in co-ordination with the Palestinian Authority, to collect $571m for emergency services across the occupied Palestinian territories.

The Humanitarian Response Plan, an umbrella financing project in its 14th year, seeks funds from international donors for programmes run by 63 UN agencies and 144 non-governmental organisations, reaching 1.6 million Palestinians who are in immediate need of education, food, shelter, clean water and protection services during 2016.

"This humanitarian operation in the occupied Palestinian territory is unique from other operations around the world," said David Carden, head of UN's OCHA-oPT office. "It originates from the impact of nearly 50 years of Israeli occupation, the main driver of humanitarian need."

Most of the aid will target 1.2 million Palestinians in Gaza, more than half of the total population in the besieged coastal Mediterranean strip. The widest margin of the appeal, $300m, will go towards food for 1.6 million Palestinians, of whom 46 percent are children.

Another 1.7 million Palestinians do not have access to clean water throughout the occupied territory.

A further 1.5 million people "have been displaced or are at risk of displacement as a result of a man-made and natural disaster", and are in need of shelter. Nearly 950,000 of those without stable housing live in Gaza.

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In the food appeal, the UN said Palestinians would be given aid parcels, cash to make purchases themselves, and infrastructure development for the agricultural industry.