The Israeli Supreme Court on Wednesday upheld the government's decision to slash fuel and electricity supplies to the Gaza Strip.

Israeli human rights groups had challenged the sanctions, which Israel says are aimed at halting ongoing rocket fire by Gaza militants. Palestinian officials say the cutbacks have harmed Gaza's already impoverished residents by causing power shortages and crippling crucial utilities.

Israel, which pulled out of Gaza in 2005 after a 38-year occupation, supplies all of Gaza's fuel and more than two-thirds of its electricity.

As militants have continued to hit Israeli towns near Gaza with near-daily rocket barrages, Israel has reduced fuel shipments but not the electricity it directly supplies. That stood to change after the court ruling Wednesday.

Israel blames the Islamic militant group Hamas, which violently seized control of Gaza last June, for the rocket fire.

The court rejected the petitioners' claim that the Israeli sanctions constitute collective punishment and target civilians in violation of international law.

"We emphasize that the Gaza Strip is controlled by a murderous terror group that operates incessantly to strike the state of Israel and its citizens, and violates every precept of international law with its violent actions," the three-judge panel wrote in its decision Wednesday.

Israel will continue to supply some fuel and electricity, and the judges said those supplies would "fulfill the vital humanitarian needs of the Gaza Strip at this time."

The court said Israel is "required to act against terror organizations in accordance with the norms of international law and abstain from deliberately harming the civilian population located in the Gaza Strip."

The Israeli groups behind the court petition, Gisha and Adalah, condemned the court decision.

"This is a dangerous legal precedent that allows Israel to continue to violate the rights of Gaza residents and deprive them of basic humanitarian needs in violation of international law," the groups said in a statement.

Fawzi Barhoum, a Hamas spokesman, said the ruling "reflects the criminal, ugly face of the occupation."

Israel, with Egypt's cooperation, has blockaded Gaza since the Hamas takeover in June. This month, Israel tightened the sanctions in response to a spike in rocket fire, restricting some humanitarian supplies which had previously been allowed in and cutting off a trickle of commercial goods still making it into Gaza from Israel.

Last week, Hamas militants broke open the blockade by blowing up the partition along Gaza's border with Egypt. The breach allowed hundreds of thousands of Gazans free access to Egypt, where they purchased huge supplies of food and fuel. On Wednesday, the border remained open for the eighth consecutive day.

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Israel said it would deliver thousands of vaccines to the Gaza Strip to combat any cattle and avian-borne diseases that may have been brought in through an influx of cows, sheep and chickens. Officials from Gaza's Agriculture Ministry could not estimate the number of animals brought into Gaza, as most have been stashed away in backyards.

Palestinian President Mahmoud Abbas traveled to Cairo at the invitation of Egyptian President Hosni Mubarak in effort to solve the border crisis. But he refused to meet with Hamas officials who were also in town for talks with the Egyptians, despite pressure from Mubarak's government to work with the militant group.

Abbas says he will not meet with Hamas until it repudiates the summer coup that brought it to power in Gaza and recognizes a 2005 international border agreement. That deal, brokered by Secretary of State Condoleezza Rice after Israel's withdrawal from Gaza, called for joint Palestinian, Israeli and EU supervision of the border.

"There will be no talks with Hamas unless they comply with the conditions we have put forward to back off their coup, to recognize international legitimacy and to accept new early elections," Abbas said.

Hamas condemned Abbas' remarks. "The statement by President Abbas today will foil any efforts to restore the Palestinian national unity," said Hamas spokesman Taher Nunu.