All but sealing Afghanistan's isolation, Saudi Arabia formally severed relations with the hard-line Taliban government on Tuesday. Stung, the Taliban denounced the Saudi move as intolerable to all Muslims and accused it of siding with "the infidel forces."

The Saudi Foreign Ministry informed Taliban charge d'affaires Molawi Muttiallah of the decision and asked him to leave the country within 48 hours, the official Saudi Press Agency said Tuesday night. It wasn't immediately clear when the two-day period began.

Meanwhile, fierce fighting was reported in northern Afghanistan, where an opposition alliance is trying to wrest strategic territory from Taliban fighters. Reports were sketchy, and the two sides made conflicting claims that could not be reconciled.

From the organization of Osama bin Laden, the accused terrorist mastermind at the heart of the hardening confrontation between Afghanistan and a U.S.-led coalition, came a volley of new threats. "Wherever there are Americans and Jews, they will be targeted," said a statement issued in the name of Naseer Ahmed Mujahed, military chief for bin Laden's al-Qaida network.

"The holy warriors are fully prepared," added the statement, faxed to news organizations in Pakistan's capital, Islamabad. Muslims everywhere, it said, "should prepare for jihad (holy war), and by the grace of God, victory will be Islam's."

Later, the Taliban's leader, Mullah Mohammed Omar, appealed to Americans to "be wise" and urged Washington to reconsider its policies toward Islamic countries, as well as its next move. His statement also was faxed to news organizations in Islamabad.

In the two weeks since suicide attackers used hijacked planes to topple the twin towers of the World Trade Center and smash a wing of the Pentagon, many Islamic nations have agreed to support the emerging U.S.-led anti-terror coalition. But the prospect of American retaliation against Afghanistan has stirred anger in much of the Muslim world.

In a drumbeat of rhetoric, bin Laden and his Afghan hosts have sought to exacerbate anti-American sentiment and portray the showdown over the exiled Saudi millionaire as a battle between the West and Islam. American and European officials, including President Bush, have worked equally hard to counter that view.

In the rugged mountains of northern Afghanistan, where the opposition alliance is battling Taliban troops, reports say heavy fighting erupted Tuesday around Mazar-e-Sharif, a city that has been in Taliban hands since the late 1990s. Accounts of the battle came from Afghan nationals working for the United Nations, said Rudy Rodrigues, head of UNICEF in neighboring Uzbekistan.

Alliance spokesman Mohammed Ashraf Nadeem, reached by telephone from the Afghan capital, Kabul, said the opposition captured several villages in the northern Sangcharak district and killed six Taliban soldiers amid duels fought with artillery, tanks, mortars and rocket launchers. Several alliance soldiers were wounded, he said.

Taliban military officials, though, scoffed at reports that Mazar-e-Sharif might fall, and Taliban-run radio said the attacks had been repulsed and the opposition suffered many casualties. It gave no details.

Pakistan has thrown in its lot with the U.S.-led anti-terror coalition, pledging crucial assistance likely to include use of its airspace and military facilities in the event of an American military strike on bin Laden's bases or the Taliban, or both.

Pakistani intelligence sources said a U.S. Defense Department delegation was sharing evidence with Pakistani authorities implicating bin Laden in the Sept. 11 terror attacks. They said the delegation, led by Air Force Brig. Gen. Kevin Chilton, was also outlining plans to use Pakistani airspace and military facilities and to exchange intelligence.

But Pakistan -- a close-up observer to two decades of brutal warfare in Afghanistan fueled by Cold War rivalries -- also expressed misgivings about using the guerrillas fighting the Taliban as a proxy army for the anti-terror coalition.

"We fear any such decision on the part of a foreign power to give assistance to one side or the other is a recipe for great suffering for the people of Afghanistan," Pakistan's foreign minister, Abdul Sattar, said.

He did not specifically mention Russia, which said Monday it was ready to provide the opposition alliance with weapons and military equipment, or the United States, which has increased its contacts with the alliance in recent days.

Even before the current crisis, the Taliban's harsh brand of Islam had led most of the world to shun it diplomatically. In recent days, that isolation intensified: the United Arab Emirates cut formal ties on Saturday, Pakistan pulled its diplomats out of Kabul on Sunday -- though it stopped short of breaking off diplomatic contact -- and Saudi Arabia severed links on Tuesday.

Pakistani President Gen. Pervez Musharraf said his government would maintain relations with Afghanistan and allow the Taliban to keep its embassy in Islamabad because "we should maintain contact with the Taliban."

"At least there should be one country who ought to be able to have access to them, to be able to engage them," he said.

In a statement carried by the official Saudi news agency, the Saudi government accused the Taliban of using their territory to "harbor, arm and encourage those criminals in carrying out terrorist attacks that horrify those who live in peace ... and spread terror and destruction in the world."

This, it said without mentioning bin Laden by name, was "defaming Muslims' reputation in the world."

The Taliban called the Saudi stance "intolerable" to all Muslims. "Saudi Arabia is the birthplace of Islam, and as such, it should refrain from siding with the infidel forces," said a statement carried on the Taliban-run news agency.