The Israeli government disclosed Tuesday that it would build 1,000 new housing units at four Jewish settlements in the West Bank, prompting sharp rebukes from Palestinians and Israeli peace activists who said the construction would strengthen Israel's grip on the West Bank and violate promises to freeze settlement growth.

The units would be in addition to 600 that Israeli officials said two weeks ago would go up soon at a major settlement just outside Jerusalem. Hundreds of other units are in the planning pipeline, according to pro- and anti-settlement activists and Israeli media reports.

Israeli officials contend that the peace plan known as the "road map" allows the population of settlements to grow, as long as the newcomers remain within existing boundaries.

The new housing units will not violate any agreements with the United States because they were permitted "in accordance with President Bush's letter of the 14th of April to Prime Minister [Ariel] Sharon, regarding the large settlement blocks," said an official in Sharon's office, who would not agree to be quoted by name.

In that letter, Bush reversed years of U.S. Middle East policy by endorsing Israel's claim to parts of the West Bank seized in the 1967 Middle East war and saying it was unrealistic to expect Israel to abandon major West Bank settlements and return to its pre-1967 boundaries. The letter did not directly address settlement growth, other than reiterating the U.S. commitment to the road map.

The road map obligates Israel to freeze "all settlement activity (including natural growth of settlements)" and to immediately dismantle settlement outposts -- estimated to number 51 by Peace Now, an advocacy group, and 28 by the Israeli government -- established since Sharon took office in March 2001. Outposts typically are small communities on remote hilltops that are established by settlers, without government permission, as the first step toward new settlements or settlement expansion.

"The Israelis have accepted the road map and its stipulations with respect to settlement activity, and we expect the Israelis to abide by their commitments," a spokesman for the U.S. Embassy in Tel Aviv said Tuesday, speaking on condition of anonymity. He would not elaborate. In Washington, White House spokeswoman Claire Buchan said the Bush administration was waiting for details on the issue from the Israeli government.

"This is an extraordinary step the government is taking -- it's an act of madness," said Yariv Oppenheimer, a spokesman for Peace Now, which opposes the settlements.

"Instead of disengagement, we're getting more settlement in the West Bank, without knowing that disengagement in Gaza will really take place," he added, referring to Sharon's plan to pull Jewish settlers and Israeli soldiers out of the Gaza Strip.

"These new housing units are destroying the road map and efforts to revive the peace process," said Saeb Erekat, a Palestinian cabinet minister and chief negotiator with Israel. "The question to President Bush is: Has the Israeli government delivered on any promises on the cessation of settlement activity?"

Israeli officials say the Palestinians are responsible for the demise of the road map because they did not rein in Palestinian militant groups and violence. Israeli officials have insisted that doing so was a prerequisite to advancing the peace plan.

Tuesday's disclosure came in the form of an advertisement by the Housing Ministry that said contracts were available for the construction of new units in four Jewish settlements: Beitar Illit, about six miles southwest of Jerusalem; Ariel, about 20 miles north of Jerusalem; Karnei Shomron, about six miles northwest of Ariel; and Maleh Adumim, the West Bank's largest settlement, about two miles east of Jerusalem.

The housing construction contracts were originally scheduled to be announced about 10 days ago, but Sharon ordered a delay so the plans could be reexamined for compliance with U.S.-Israeli agreements, Israeli government officials said.

Following Tuesday's disclosure, settlement leaders accused the prime minister of playing politics with the new units to curry favor with hard-line nationalist and religious members of his Likud Party.

During a Likud convention on Wednesday, members are scheduled to vote in a secret, nonbinding ballot on whether to form a coalition government with the more dovish Labor Party. Such a coalition would significantly improve Sharon's chances of winning government support for his Gaza Strip disengagement plan.

Airstrike in Gaza Kills

Five, Including Militants

Israel's air force launched an attack near a Gaza City home early Wednesday, killing at least five people, including three Palestinian militants, according to witnesses and officials on both sides. Seven people were wounded, four critically.

Palestinians said an explosion struck near a house belonging to Ahmed Jabari, an activist in the Islamic Resistance Movement, known as Hamas.

Two of the dead were identified as Hamas militants and another as a member of the militant group Islamic Jihad. The two others were not immediately identified.

In a separate development, Israeli soldiers on Tuesday shot and killed a 9-year-old Palestinian boy in Nablus as he sat on the front steps of his home eating a sandwich, relatives said.

Nearby youths had been throwing stones at the troops, the boy's aunt said. An Israeli military official said soldiers fired at Palestinians throwing concrete blocks, stones and a firebomb in three separate incidents, but was not aware that anyone was killed.