The Islamic militant group Hamas (search) released a videotape of a shadowy senior commander who has eluded Israeli forces for more than a decade, taking another shot in a Palestinian power struggle over who should get credit for Israel's pullout from Gaza.

The man, identifying himself as fugitive bombmaker Mohammed Deif (search), described Israel's withdrawal as a victory for armed resistance, rejected calls for his group to disarm and vowed to continue attacking Israel until the Jewish state is erased from the map.

"You are leaving Gaza today in shame," he said in comments directed at Israel (search). "Today you are leaving hell. But we promise you that tomorrow all Palestine will be hell for you, God willing."

Israeli officials said the tape underscored the need for the Palestinian Authority to crack down on militants. Palestinian officials said despite the comments, Hamas remained committed to a 6-month-old cease-fire.

In Crawford, Texas, meanwhile, President Bush issued a strong call for the Palestinian Authority to crack down on militant groups in the wake of the pullout from the Gaza Strip.

"The Palestinians must show the world that they will fight terrorism and govern in a peaceful way," Bush said in his weekly radio address.

With Palestinian legislative elections set for January, Hamas and Palestinian leader Mahmoud Abbas' Fatah party are locked in a bitter struggle over who deserves credit for the Gaza withdrawal. Israel removed the last of its 21 Gaza settlements this week and is expected to complete the pullout by early October.

Hamas argues that years of suicide bombings and rocket attacks drove the Israelis out. Abbas, who is a vocal critic of violence and hopes to resume peace talks with Israel, has tried to shore up his standing with promises that he can improve life in Gaza after the withdrawal.

In the tape, Deif praised the armed struggle against Israel.

"Without this jihad and this steadfastness, we did not achieve the liberation of the Gaza Strip," he said, adding that attacks should continue until Israel is eliminated.

Hamas has killed hundreds of Israelis in attacks since fighting resumed in 2000.

In an open challenge to Abbas, Deif also rejected calls for Hamas to disarm, though he said differences between Palestinian groups should be resolved peacefully.

"We warn against touching these weapons, and want to keep them as an effective element to liberate the rest of our homeland," he said. "We want to use dialogue to solve any differences in order to protect our Palestinian blood and our national achievement."

Abbas has said all militant groups should give up their weapons after the Gaza pullout, but he has been hesitant to confront them with force.

Deif, widely believed to be at the top of Israel's most-wanted list, is responsible for the deaths of dozens of Israelis in suicide bombings. He has survived at least two Israeli assassination attempts, most recently a 2002 missile strike in which he lost an eye.

There was no way to positively identify the figure in the video as Deif because a dark shadow covered his face. Deif has been in hiding since 1992 and the only known photos of him were taken in the 1980s.

But the high quality of the video, which was stamped with the logo of the Hamas military wing, as well as the similarity of the voice to previous recordings indicated the tape was authentic.

The group would not say when Deif made the tape, citing security concerns. But it had boasted for nearly two weeks that Deib was going to make a public statement, and militants delivered the tape to The Associated Press offices in Gaza City. The group also posted a transcript of his comments on its Web site.

Tawfiq Abu Khoussa, a spokesman for the Palestinian Interior Ministry, which is in charge of security in Palestinian-controlled areas, said there was nothing new in the tape.

"It wasn't secret that Hamas military wing in Gaza exists, and Mohammed Deif is still alive," he said. "All Palestinian factions are committed to the truce, including Hamas, and we see nothing new in Hamas' position toward the truce."

Hamas has scaled back its activities since the truce declaration, but Israel says the group is using the lull to revamp its military capabilities. Israel has said any resumption of peace talks will depend on Abbas' ability to disarm Hamas and other militant groups.

Gideon Meir, a senior official with the Israeli Foreign Ministry, said the videotape threatened to derail the recent atmosphere of goodwill after the Gaza pullout.

Deif's "declaration proves again why the Palestinian Authority must fulfill its duty and fight the Hamas, Islamic Jihad and Al Aqsa Martyrs' Brigades," he said, referring to the major armed Palestinian groups.

Abbas met at his West Bank headquarters Saturday with Israeli lawmaker Ephraim Sneh, a leader in the Labor Party, the junior partner in the Israeli coalition government.

Sneh said the two men discussed ways to proceed with peace talks after the Gaza withdrawal. He declined to provide details, but Israeli media reported that Abbas promised to demand that Hamas disarm if it wants to join the Palestinian government.