The United States on Thursday urged Israel not to exacerbate the humanitarian situation in the Gaza Strip, where Israel has scaled down its energy supply as it pursues rocket launchers in the territory.
"We understand Israel's right to defend itself but we do not think that action should be taken that would infringe upon or worsen the humanitarian situation for the civilian population in Gaza," said US State Department spokesman Tom Casey.
"I am sure we will continue to convey that position to them."
Israel on Thursday began reducing by the electricity it supplies to Gaza via high-tension power lines. "The Israeli electricity company on Thursday evening reduced by about 1% the electricity supplied by high tension line to the Gaza Strip," Defense Ministry spokesman Shlomo Dror said.
Speaking in Israel, Defense Minister Ehud Barak vowed that "if the rocket fire from Gaza continues, we will intensify our operations and strikes against the other side, until a solution is found."
HRW: Israel collectively punishing Gaza populace
Ahead of the reduction the New York-based Human Rights Watch (HRW) group said in a new report that the planned "cuts of fuel and electricity to Gaza... amount to collective punishment of the civilian population."
Israel began reducing the amount of fuel it supplied to Gaza in late October after declaring the coastal strip a "hostile entity" following its takeover by Hamas.
The Defense Ministry said it would reduce by 5% the amount of electricity it supplies to Gaza in one of 10 lines, with similar cuts in other lines to follow in the coming weeks.
The cuts will eventually reduce the 120 megawatts Israel supplies to the increasingly isolated territory by 1.5 megawatts.
Israel says the measures are aimed at stopping Gaza militants from firing rockets into Israel and has pledged not to allow a humanitarian disaster in the territory where most of the population depends on foreign aid.
"Israel views restricting fuel and electricity to Gaza as a way to pressure Palestinian armed groups to stop their rocket and suicide attacks," HRW's Middle East director Joe Stork said in the statement.
"But the cuts are seriously affecting civilians who have nothing to do with these armed groups, and that violates a fundamental principle of the laws of war," he said.
The Israeli human rights group B'Tselem also condemned the move, calling on both Israel and Palestinian militants to "leave civilians out of the cycle of war.
"We admit the right of Israel to defend its civilians against these attacks, but Israel has to use means allowed under international humanitarian law," the group said.