More than 50 international aid groups and U.N. agencies have issued a joint appeal for an end to the Israeli blockade of the Gaza Strip. The signatories include Amnesty International, Save the Children, the World Health Organization, Oxfam, the Office of the High Commissioner for Human Rights and five other U.N. bodies. Issuing the appeal on Thursday, U.N. and aid officials said Israel’s repeated attacks on Gaza have poisoned its water supply.

Filippo Grandi: “It has been said many times, but today is an important day in which to repeat it, the blockade is illegal according to international law.”

Charles Da Salvia: “Now, today, 95 percent of the coastal aquifer, 95 percent, the sole source of fresh water available for Palestinians in the Gaza Strip, is not safe to drink.”

Thursday’s appeal came on the fifth anniversary of the blockade, when Israel sought to punish Gaza after Hamas preempted a U.S.-backed coup to subvert the results of 2006 Palestinian elections.