CAIRO — Osama bin Laden warned Iraq’s Sunni Arabs against fighting Al Qaeda and vowed to expand the terror group’s holy war to Israel in a new audiotape today, threatening “blood for blood, destruction for destruction.”

Most of the 56-minute tape dealt with Iraq, apparently Al Qaeda’s latest attempt to keep supporters in Iraq unified at a time when the America military claims to have Al Qaeda’s Iraq branch on the run.

The tape did not mention Pakistan or the assassination of Benazir Bhutto, though Pakistan’s government has blamed Al Qaeda and the Taliban for her death on Thursday.

But Mr. bin Laden’s comments offered an unusually direct attack on Israel, which has warned of growing Al Qaeda activity in Palestinian Arabs territory. The terror network is not believed to have taken a strong role there so far.

“We intend to liberate Palestine, the whole of Palestine from the (Jordan) river to the sea,” he said, threatening “blood for blood, destruction for destruction.”

“We will not recognize even one inch for Jews in the land of Palestine as other Muslim leaders have,” Mr. bin Laden said.

In Iraq, a number of Sunni Arab tribes in western Anbar province have formed a coalition fighting Al Qaeda-linked insurgents that American officials credit for deeply reducing violence in the province. The American military has been working to form similar “Awakening Councils” in other areas of Iraq.

A White House spokesman, Tony Fratto, said Mr. bin Laden’s tape shows that Al Qaeda’s aim is to block democracy and freedom for all Iraqis.

“It also reminds us that the mission to defeat Al Qaeda in Iraq is critically important and must succeed,” Mr. Fratto said. “The Iraqi people — every day, and in increasing numbers — are choosing freedom and standing against the murderous, hateful ideology of AQI. And we stand with them.”

Several hours before the tape was issued, the top American commander in Iraq, General David Petraeus, said Al Qaeda was becoming increasingly fearful of losing the support of Sunni Arabs and had begun targeting the leaders of the Awakening Councils.

General Petraeus said Al Qaeda attaches “enormous importance” to “these tribes that have turned against them, and to the general sense that Sunni Arab communities have rejected them more and more around Iraq.”

“They are trying to counter this and they have done so by attacking them,” which is increasingly turning Sunnis against Al Qaeda, he said.

Iraq’s interior ministry spokesman, Major General Abdul Kareem Khalaf, claimed that 75% of Al Qaeda in Iraq’s terrorist network had been destroyed in 2007, and gave some of the credit to the rise of anti-Al Qaeda in Iraq councils.

General Petraeus said that despite a number of successes against Al Qaeda in recent months, the terror network remains “the most significant enemy Iraq faces because it carries out the most horrific attacks.”

In the audiotape, Mr. bin Laden denounced Abdul-Sattar Abu Risha, the former leader of the Anbar Awakening Council, who was killed in a September bombing claimed by Al Qaeda.

“The most evil of the traitors are those who trade away their religion for the sake of their mortal life,” Mr. bin Laden said.

Mr. bin Laden said American and Iraqi officials are seeking to set up a “national unity government” joining the country’s Sunnis, Shiites, and Kurds.

“Our duty is to foil these dangerous schemes, which try to prevent the establishment of an Islamic state in Iraq, which would be a wall of resistance against American schemes to divide Iraq,” he said.

He called on Iraq’s Sunni Arabs to rally behind the Islamic State of Iraq, the insurgent umbrella group led by Al Qaeda. Besides the Awakening Councils, some Sunni insurgent groups that continue to fight the Americans have rejected the Islamic State.

Mr. bin Laden said Sunnis should pledge their allegiance to Abu Omar al-Baghdadi, the little known “emir” or leader of the Islamic State of Iraq. American officials have claimed that al-Baghdadi does not exist, saying Al Qaeda created the name to give its coalition the illusion of an Iraqi leadership.

“Failure to give allegiance to the emir after he has been endorsed leads to great evils,” Mr. bin Laden warned. “Emir Abu Omar would rather have his neck severed than betray the Muslims … Emir Abu Omar and his brothers are not one of those who accept compromise or meeting the enemy halfway.”

The authenticity of the tape could not be independently confirmed. But the voice resembled that of Mr. bin Laden. The tape was posted on an Islamic militant Web site where Al Qaeda’s media arm, Al-Sahab, issues the group’s messages.

The tape was the fifth message released by Mr. bin Laden this year, a flurry of activity after he went more than a year without issuing any tapes. The messages began with a September 8 video that showed bin Laden for the first time in nearly three years. The other messages this year have been audiotapes.

In an October tape, Mr. bin Laden sought to patch up splits between Iraqi insurgent factions, urging them to unite with the Islamic State of Iraq — the insurgent coalition led by Al Qaeda. He took a conciliatory stance, chiding even Al Qaeda’s followers for being too “extremist” in their positions toward other insurgents.

Mr. bin Laden’s deputy, Ayman al-Zawahri, took a sharper tone in a December 16 video, branding as “traitors” those who work with the anti-Qaeda tribal councils and calling for Sunnis to purge anyone cooperating with the Americans.