"The ICRC's opinion is that the West Bank barrier, in as far as its route deviates from the Green Line into occupied territory, is contrary to IHL (international humanitarian law)," the International Committee of the Red Cross said in a statement on Wednesday.
The statement came less than a week before a UN court in the Hague is due to examine the legality of the barrier, dubbed the "apartheid wall" by critics.
"The ICRC therefore calls upon Israel not to plan, construct or maintain this barrier within occupied territory" as this would have serious humanitarian and economic consequences for thousands of Palestinians.
The ICRC, which guarantees the Geneva Conventions on the rules of war, generally seeks to remain neutral, and rarely expresses an opinion on issues directly linked to the policies of states.
It based Wednesday's statement on Israel's responsibility as an occupying power.
"The barrier deprives thousands of Palestinian residents of
adequate access to basic services such as water, health care and education, as well as sources of income such as agriculture and other forms of employment," where it deviates from the so-called Green Line into occupied territory, the statement said.
The Green Line between Israel and the West Bank marks the
armistice lines at the end of the 1948 Arab-Israeli war.
The statement by the ICRC was the first time the charity had condemned the barrier, which variously consists of lengths of razor wire, electronic fencing, concrete and ditches.
The Red Cross said "Palestinian communities situated
between the Green Line and the barrier are effectively cut off from the Palestinian society to which they belong."
"The construction of the West Bank barrier continues to give
rise to widespread appropriation of Palestinian property and
extensive damage to or destruction of buildings and farmland."
"The problems affecting the Palestinian population in their
daily lives clearly demonstrate that it runs counter to Israel's
obligation under IHL to ensure the humane treatment and well-being of the civilian population living under its occupation," the statement said.
More than 200,000 Palestinians are already suffering the humanitarian consequences of the separation barrier, according to the United Nations.
The barrier has cut off villages
from markets and schools
The 180km segment completed so far has cut off villages from markets, medical services and schools in the northern West Bank.
It has resulted in the confiscation of 11,4000 dunums (one dunum equals 1000 square metres) of privately-owned Palestinian land and in the destruction of 102,320 trees, a report by the UN Office for the Coordination of Humanitarian Affairs (OCHA) has found.
As to the projected effects of the barrier once it is completed, OCHA estimated in December that 30% of the West Bank population, or about 680,000 people, will be "directly harmed".
Some 274,000 Palestinians in 122 villages and towns will either live in closed areas - between the barrier and the Green Line -or in 12 enclaves entirely surrounded by the fence.
Another 400,000 will have to cross the separation line to reach their workplaces.
The barrier is expected to stretch more than 700km by the time it is completed at the end of next year.
The International Court of Justice, often referred to as the
world court, is due to begin sitting on the legality of the
separation barrier from next Monday, but Israel has decided to boycott the hearing by not sending any legal representatives to the Hague.
While condemning acts of "terrorism", which Israel says are the reason for the barrier's construction, and adding that Israel's right to security could not be disputed, the ICRC warned:
"The measures taken by the Israeli authorities linked to the construction of the barrier in occupied territory go far beyond what is permissible for an occupying power."