JERUSALEM — Israel unveiled a new tactic this week aimed at deterring Palestinians from firing rockets out of the Gaza Strip. It will cut off Gaza’s electricity bit by bit as a pressure tactic every time rockets hit Israeli territory.

Israel provides more than half of Gaza’s electricity, and any power cutoff is sure to make life more difficult people in the impoverished region — and draw harsh international criticism.

The retaliation would begin with short cutoffs that would gradually increase for continued rocket fire, but a lengthy power blackout would not be imposed, defense officials said.

Israel’s government declared Gaza a “hostile territory” last month, clearing the way for sanctions. The decision came after the June takeover of the territory by HAMAS and almost daily rocket fire by Gaza militants at towns in southern Israel.

A rocket exploded on a home in the southern Israeli town of Sderot on Tuesday.

On Wednesday, the Israeli military killed two members of a Palestinian rocket squad in Gaza, HAMAS security and hospital officials said. The Israeli military said it attacked after rocket fire from the area.

The extremist group Islamic Jihad said it fired rockets a few minutes before the Israeli attack. It said the two dead were 15 years old. Often teenagers go out to get launchers after rockets are fired.

Early Thursday, Israeli soldiers killed two HAMAS militants in a clash near Khan Younis in Gaza, Hamas officials and the military said.

Israel’s deputy defense minister, Matan Vilnai, said it was time to increase pressure on the militants over the rocket fire.

“It’s clear that we have to cut off … the supply of electricity and the supply of fuel,” Vilnai told Israeli Army Radio. “We will dramatically reduce the flow of electricity from Israel over several weeks.”

Vilnai headed the team that formulated the plan, which was expected to be formally approved Thursday by Defense Minister Ehud Barak, Israeli officials said. They agreed to discuss the matter only if not quoted by name because the plan had not been officially adopted.

The officials said Israel would start by cutting off electricity for 15 minutes after each rocket barrage, lengthening the blackout each day as long as rocket fire continued. It was not known when the policy would take effect.

Alaa Araj, an economic adviser to Gaza’s Hamas government, said the Israeli measure would violate human rights by hurting the strip’s entire population. “Society will be drawn into darkness and daily life will be crippled,” he said.

Israel can expect international criticism if it goes ahead with the plan.

When it first announced its intention to impose sanctions last month, U.N. Secretary-General Ban Ki-moon criticized the idea in unusually strong language, saying that “would be contrary to Israel’s obligations toward the civilian population under international humanitarian and human rights law.”

Israel counters that it must act to protect its civilians suffering from near-daily barrages of crude rockets fired from Gaza, even after it pulled its army and settlers out of the territory in 2005.

Despite its economic blockade of Gaza and regular military incursions and airstrikes, Israel has been unable to halt the rocket fire, which has killed 12 Israelis in six years and severely disrupted life in the area.

Most of the rockets have been launched by militants from Islamic Jihad, with HAMAS limiting itself mainly to firing mortar shells at border crossings. But Israel charges that HAMAS has done nothing to halt the rockets, and Israel holds it responsible because it controls Gaza.

Vilnai said Israel would not cut off power to hospitals and other vital installations. But Israel hopes the measure will convince Gazans they need to do more to stop the rocket fire.

Akram Hamad, an unemployed resident of the northern Gaza town of Beit Hanoun, said the Israeli decision amounted to “collective punishment,” but would not deter the rocket fire, which he termed “legitimate self-defense.”

“This can’t be accepted by international organizations, to cut electricity from the whole town because a rocket is fired,” he said.

It is unclear what effect an Israeli cutoff would have. Gaza already suffers from electricity shortages and many buildings have backup generators.

Also Wednesday, Palestinian gunmen in a passing car seriously wounded an Israeli soldier waiting at a bus stop near the West Bank settlement of Ariel, the army said. A previously unknown offshoot of Fatah, the movement headed by Palestinian President Mahmoud Abbas, took responsibility for the shooting in a phone call to The Associated Press.

Addressing Israel’s parliament Wednesday, Prime Minister Ehud Olmert expressed hope the planned Mideast conference this year will mark “the beginning of the end of the conflict between us and the Palestinians.”

Olmert said, however, that peace cannot be made at conferences, reflecting Israel’s attempts to scale back expectations for the gathering called by President Bush.

Israeli and Palestinian negotiating teams met Wednesday, Palestinian negotiator Saeb Erekat said. No agreements were announced.