GAZA CITY, Gaza Strip, (AP)- Human rights groups challenged Israel’s reduction of fuel supplies to Gaza and its intention to cut back on electricity, and Palestinians warned the measures could lead to a humanitarian crisis.

The Israeli Supreme Court on Sunday gave the state five days to respond to the appeal from human rights groups for an injunction to halt the energy cutbacks, said Sari Bashi of Gisha, one of the 10 groups that filed the petition.

Palestinians said Israel cut fuel supplies by 30 percent on Sunday, though defense officials said the cut was only about 11 percent. Israel hopes the move will pressure Gaza’s Hamas rulers to halt near-daily rocket attacks by militants against Israeli towns.

Binyamin Ben-Eliezer, Israel’s infrastructure minister, said Monday that the cutbacks were a final attempt to avoid a military operation that would cause scores of civilian casualties.

“What’s the alternative? The alternative is that tomorrow or the next day we’ll be forced to bring three or four divisions and go into Gaza,” Ben-Eliezer said in an interview on Israel Radio. “What will the results be then?”

“There’s nothing we haven’t tried,” he said.

Last month the Israeli government declared Gaza a “hostile entity” and approved the plan for cutoffs as a response to the rocket fire. Israeli Defense Minister Ehud Barak gave the final go-ahead last week.

The Israeli Defense Ministry said in a statement Sunday that the Sufa crossing between Gaza and Israel has been closed. That crossing is used for transporting cargo in and out of Gaza. Its closing left only a smaller cargo crossing in operation.

Israel says it holds the militant Islamic Hamas, which seized control of Gaza in June, responsible for the continued rocket fire. Smaller militant groups have carried out most of the rocket attacks, with Hamas militants firing mortars at border crossings. But Hamas has done nothing to stop the rocket fire.

The fuel cut drew harsh condemnation from Palestinians in Gaza, which relies on Israel for all its fuel and more than half its electricity.

“This is a serious warning to the people of the Gaza Strip. Their lives are now in danger,” said Ahmed Ali, deputy director of Gaza’s Petroleum Authority, which distributes Israeli fuel shipments to private Palestinian companies. “The hospitals, water pumping station and sewage will now be affected by the lack of fuel.”

He said Gaza keeps about four days of fuel reserves. Ali said he feared that companies would hoard supplies or raise prices.

The impoverished territory is expected to be hit hard by the shortage of fuel, which is used for driving, cooking and for the private generators that are ubiquitous in Gaza because of constant power outages.

Fuel from Israel also powers Gaza’s only electric plant, which provides a quarter of the territory’s electricity and will now have to ration its reserves.

In their appeal, the 10 human rights groups contended, “Deliberately obstructing the civilian infrastructure in the Gaza Strip is illegal.” They say Israel controls Gaza land, sea and air corridors and should be considered responsible for the fate of the people there, though Israel withdrew from Gaza in 2005.

Israel has already severely restricted trade with Gaza, shutting down most of the territory’s industry, and conducts frequent airstrikes and small ground operations against militants. Early Monday, Israeli troops killed a Hamas field commander in southern Gaza, Hamas announced. The military confirmed that soldiers clashed with militants in the area.

But the measures have had little effect on the rocket barrages, which have killed 12 people in recent years and disrupted life for Israelis living near Gaza.

Alaa Araj, an economic adviser to the Hamas government, called Israel’s decision a sign of “hysteria.”

“It wants to totally disable the Palestinian society,” Araj said.

Israeli government spokeswoman Miri Eisin said Israel will “not allow in any way” a humanitarian crisis to develop in Gaza. “The terrorists are bombarding the crossing points of the fuels, and we do not feel the need to supply the terrorists,” she said.

At a taxi depot in downtown Gaza, drivers agreed the cutoff will mean price hikes but couldn’t agree on who to blame.

“Israel wants us to give in. We will not. If the rockets were useless, Israel wouldn’t have been that angry,” said Mohammed al-Haddad.

But another driver who would identify himself as Abu Nidal blamed the rivalry between Hamas and Fatah. “If they can’t manage things, and are only making people suffer, they should both step down,” he said.

Despite its conflict with Hamas, the moderate West Bank government of Palestinian President Mahmoud Abbas condemned the latest Israeli measures.

“We consider it a threat to the peace process and we have initiated contacts with Israel to stop it,” said Palestinian Foreign Minister Riad Malki.