JERUSALEM - After weeks of restraint, Israel said Wednesday that it will renew attacks on rocket-launching militants in the Gaza Strip, threatening to derail an already shaky, month-old truce.

A new round of fighting in Gaza could undermine Israel's efforts to bolster the moderate Palestinian president, Mahmoud Abbas, in his standoff with the Islamic militants of Hamas who control the Palestinian government and legislature.

The Israeli decision, made at a meeting of top officials, came hours after a Palestinian rocket seriously wounded two Israeli teenage boys in the southern town of Sderot, next to Gaza.

Prime Minister Ehud Olmert's office said Israeli retaliation would be limited to "pinpoint" operations meant to foil rocket launches. "At the same time, Israel will continue to abide by the cease-fire," the statement said.

The truce was reached Nov. 26, ending five months of deadly fighting in Gaza. But since the cease-fire declaration, more than 60 rockets have been fired at Israel, the army said.

Israel has so far refrained from responding, but Olmert had warned in recent days his patience was wearing thin. The wounding of the two boys late Tuesday increased pressure on Olmert from political opponents and members of his Cabinet to take action.

Hamas government spokeswoman Ghazi Hamad denounced the Israeli decision to "continue their aggression against our people," but added: "We still believe that this agreement is alive, and both sides should respect this agreement because it is (in) the interest (of) our people."

Hamad's comments were directed not only at Israel, but also at the rival militant group Islamic Jihad, which has been responsible for most of the rocket fire. After the Israeli threat of retaliation, Islamic Jihad fired another rocket. There were no reports of damage or injuries.

The fate of the truce appeared to lie in the hands of Islamic Jihad, a tiny Iranian-backed group that wants to destroy Israel and replace it with an Islamic state. Over the past two years, Islamic Jihad has repeatedly sabotaged efforts to halt violence, firing rockets and carrying out a string of suicide bombings.

Islamic Jihad officials said the rocket fire was meant to avenge Israeli arrest raids in the West Bank, which is not covered by the truce. The group also believes that igniting conflict with Israel will help unite Palestinians after a bitter round of infighting that has killed 17 people this month.

"That's one of the main reasons for resuming attacks," said Abu Ahmad, a spokesman for the group.

The infighting has pitted Hamas, which also rejects Israel's existence, against Abbas' more moderate Fatah. Hamas, which won legislative elections early this year, controls most government functions. Abbas, who was elected in a separate presidential vote, hopes to restart peace talks with Israel.

Israel's threats of retaliation could harm its recent efforts to bolster Abbas in his standoff with Hamas. After meeting the Palestinian leader last weekend, Olmert agreed to release $100 million in frozen Palestinian tax money and to ease travel restrictions on Palestinians in the West Bank as goodwill gestures.

Israeli Foreign Minister Tzipi Livni said limited military strikes in Gaza should not lead to widespread conflict.

"As long as operations are prudent and pinpointed, there is no reason for things to deteriorate," Livni said at a news conference with visiting Egyptian Foreign Minister Ahmed Aboul Gheit.

Aboul Gheit, in Jerusalem to prepare for a Jan. 4 summit between Olmert and Egyptian President Hosni Mubarak, urged Israel to show restraint. "We need to continue with the peace process because that is the way to progress," he said.

In Egypt, Abbas said he had proposed opening secret "backdoor" peace negotiations with Israel.

"It is the right time to talk about this issue seriously," Abbas told reporters after he talked with Egyptian President Hosni Mubarak. Abbas said he raised the issue with Olmert last weekend, and the Israeli leader promised to consider it.

There was no immediate Israeli reaction.

The endangered truce in Gaza ended five months of fighting that erupted after Hamas-linked gunmen tunneled into Israel, killed two soldiers and captured a third. Egypt, which frequently mediates between Israel and the Palestinians, has been trying to negotiate the release of the soldier, Cpl. Gilad Shalit.

At Wednesday's news conference, Aboul Gheit said that "we are sure that he is still alive."

Shalit has not been seen or heard from since he was captured, though Israeli officials have said they believe the soldier is alive.

"What he said is nothing new," Noam Shalit, the soldier's father, told The Associated Press. "I hope there is more behind it ... I wish we could know more."