srael's Supreme Court on Wednesday upheld the government's decision to reduce fuel and electricity deliveries to the Gaza Strip as a form of "economic warfare" against the armed Hamas group in control there.

In doing so, the three-judge panel rejected the arguments of Israeli and Palestinian human rights groups that the blackouts and shortages caused by the cuts represent a form of collective punishment against Gaza's 1.5 million residents.

"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 judges wrote.

The ruling clears the way for the Israeli government to begin reducing its delivery of electricity to Gaza on Feb. 7, and to continue cutting back the shipments of fuel used to run Gaza's power plant, generators and vehicles. Most of Gaza's electricity is supplied by power lines from Israel.

The judges said the reduced services were warranted as retaliation for rocket attacks from Gaza on southern Israel. Israel's Defense Ministry, in court filings, described the government's action against Gaza as "economic warfare."

Israel had assured the court that it would deliver enough supplies into Gaza to cover "vital humanitarian needs" there, the judges wrote. Gaza officials say the pending cuts would lead to blackouts at hospitals.

The ruling "violates fundamental principles of international law which forbid collective punishment and targeting civilians," said Sari Bashi, head of Gisha, an Israeli rights group.

Israel has sharply limited the movement of people and goods in and out of Gaza since June, when Hamas prevailed in days of fighting with Fatah, its former partner in a Palestinian power-sharing government. Hamas has run a parallel administration in Gaza since then, while Palestinian Authority President Mahmoud Abbas, a Fatah leader, governs in the West Bank.

Israel imposed a full blockade on Gaza for 4 1/2 days this month, turning back all shipments of food and fuel. Palestinian gunmen responded by blowing up much of the border wall between Gaza and Egypt, allowing hundreds of thousands of Gazans to flow into Egypt to shop for goods scarce in the strip.

Hamas and Fatah officials traveled to Cairo on Wednesday, each side trying to negotiate a deal that would allow it to help control Gaza's border with Egypt.

After meeting with Egyptian President Hosni Mubarak, Abbas told reporters that Hamas should not be allowed that role. The Islamic movement is considered a terrorist organization by Israel and the United States.

But Abbas's government, with no real influence in Gaza, would have little ability to control the border without the cooperation of Hamas. "Talking about a partial role" for Hamas "contradicts reality," Mahmoud al-Zahar, a senior Hamas official, told reporters.