An ax-wielding Palestinian militant went on a rampage Thursday in a Jewish settlement in the West Bank, killing an Israeli 13-year-old and wounding a 7-year-old boy before fleeing the area.

The attack posed an important test for Israel's new prime minister, Benjamin Netanyahu, who has promised a firm hand against militants and expressed skepticism about prospects for peace. Government spokesman Mark Regev called it a "senseless act of brutality against innocents."

Police and military units were searching for the attacker, according to police spokesman Micky Rosenfeld and army officials. Army forces were operating in the nearby village of Safa, searching houses and taking village residents to a central school yard. The military said all roads around the settlement of Bat Ayin were closed.

A resident of the settlement, identifying himself only as Avinoam, said he fought off the attacker.

"First I grabbed his hand with the ax so he wouldn't kill me," he told Channel 10 TV. "I fell down, and then I managed to get up. ... At some stage I managed to grab the ax from his hand" before the attacker escaped, he said. The assailant had "a lust for murder in his eyes," he said.

A 13-year-old boy was killed and a 7-year-old boy was badly wounded, Israeli emergency services said.

A murky militant group calling itself the Martyrs of Imad Mughniyeh claimed responsibility for the attack in an e-mail sent to the AP.

The group is named for a Hezbollah mastermind killed in Syria last year in what is believed to have been an assassination by Israeli intelligence. It has claimed a number of past attacks, but Israeli defense officials believe it is likely a name used by other groups to avoid Israeli reprisals.

The e-mail said the militant group Islamic Jihad was also involved, but the group's spokesman in Gaza would not comment.

The attacker apparently entered Bat Ayin, south of Jerusalem, unhindered. The settlement is home to religious settlers who have refused to build a security fence around their community, as is the rule in most other settlements, saying fences are a sign of insecurity.

The attack was likely to heighten tensions between the Palestinians and Israel's new hard-line government, which has already voiced skepticism about peace negotiations in its first days in office.

"The new Israeli government will have a zero tolerance policy toward these sorts of attacks and will refuse to accept them as routine," Regev said. "The Palestinian leadership must both in word and in deed too have a zero tolerance policy to this sort of attack to demonstrate its commitment to peace and reconciliation."

Netanyahu was elected to office on a campaign that criticized his predecessor's peace negotiations with Palestinian President Mahmoud Abbas.

Since then Netanyahu has said he will seek peace, but has given few details about his vision for a final agreement. He has specifically refused to endorse the idea of an independent Palestinian state — a key demand of the Palestinians and centerpiece of U.S. diplomacy in the region.

On Wednesday, Netanyahu's foreign minister, Avigdor Lieberman, said Israeli concessions to the Palestinians would only bring more war. He also rejected the previous government's peace talks, launched at a U.S.-sponsored conference in 2007.

Netanyahu hasn't commented publicly on Lieberman's statement. But a close Netanyahu ally, Cabinet minister Gilad Erdan, said Thursday that Lieberman's comments largely reflected the position of the prime minister's Likud Party.

Israel's former chief peace negotiator, Tzipi Livni, said Lieberman's scathing rejection of recent negotiations shows the new government is not a partner for peace with the Palestinians.

"What happened yesterday is that the Israeli government announced that Israel isn't relevant, isn't a partner," Livni, the former foreign minister, told Army Radio.

The appointment of the ultranationalist Lieberman has angered Palestinians and raised international concerns because of his hard-line positions on peace and an election campaign that was widely seen as racist.

His comments on Wednesday signaled a difficult road ahead for President Barack Obama's Mideast policy, especially its push for a Palestinian state.

U.S. Secretary of State Hillary Rodham Clinton called Lieberman early Thursday, according to Lieberman spokeswoman Irena Etinger. The conversation was conducted in a "good atmosphere," and the two agreed to meet as soon as possible, Etinger said. She would not say what issues were discussed.