Israel said it was reducing electrical power to the Gaza Strip on Friday as part of its plan to sever economic ties with the territory.
The move was the latest in a series of Israeli steps that increases pressure on Gaza, ruled by the Islamist Hamas since last June and the source of repeated rocket attacks into the Jewish state.
Critics have accused Israel of imposing a blockade that amounts to "collective punishment" of the population of the territory after it cut fuel to Gaza's main power plant last month, leading to blackouts.
"We are trying to reduce the Gaza Strip's dependence on Israel in many fields ... the High Court ruled that we are acting in a correct and appropriate manner," deputy Defence Minister Matan Vilnai said.
A spokesman for Vilnai said Israel would reduce electricity on one of ten high-power lines by less than one megawatt by the end of Friday. It would eventually reduce power by some five percent of the 124 megawatts it supplies the Gaza Strip.
"This is not punishment ... we have disengaged from them by pulling out our troops and settlers and now we want them to start looking after themselves, they have their own power station, they get power from Egypt, we want them to ... stop relying on Israel," spokesman Eitan Ginsburg said.
Israel Radio reported on Thursday night that the power reduction had already begun.
Ginsburg said that apart from Israel's 124 megawatts, a local power station in Gaza City produced 64 megawatts and Egypt supplied 17 megawatts.
Asked to comment, U.S. State Dept spokesman Tom Casey said he was not familiar with the Israeli decision, but added: "We understand Israel's right to defend itself, but we do not think that actions should be taken that would infringe upon or worsen the humanitarian situation for the civilian population in Gaza."
