Usama bin Laden on Monday vowed to lead a holy war to crush what he called a "new crusade and Jewish campaign led by the big crusader Bush under the flag of the cross."
"I announce to you, our beloved brothers, that we are steadfast on the path of jihad (holy war) with the heroic, faithful Afghan people, under the leadership of Mullah Mohammed Omar," bin Laden said in a statement provided to Qatar's Al-Jazeera satellite channel. The statement was signed by bin Laden and dated Sunday.
Bin Laden, believed in hiding in Afghanistan, is the suspected mastermind behind the September 11 terrorist attacks on the World Trade Center and the Pentagon. He often communicates with the outside world through Al-Jazeera, known among Arabs for its wide reach and its independent and aggressive editorial policies.
Omar is the leader of the Taliban militia that rules most of Afghanistan. On Monday, Omar said the United States must withdraw its forces from the Persian Gulf and side with the Palestinians over Israel if it wants to eliminate terrorist threats against Americans.
In his statement, Bin Laden said he was informed that some "of our Muslim brothers in Karachi (Pakistan) were killed while expressing their opposition to the aggression of the American crusade forces and their allies on Muslim lands in Pakistan and Afghanistan."
He said he was praying to God that they would be accepted as martyrs. "Their children are my children, and I will be their caretaker," bin Laden said.
"We hope that they are the first martyrs in Islam's battle in this era against the new crusade and Jewish campaign led by the big crusader Bush under the flag of the cross."
Demonstrations have been held in the Pakistani cities of Karachi, Peshawar and Quetta by Pakistanis who view bin Laden as an Islamic hero.
Bin Laden said that he was calling on all Muslims in Pakistan to use all they possess and all their effort to stop American troops from going into Pakistan and Afghanistan.
Bin Laden has twice denied involvement in the September 11 attacks on New York and Washington. The United States has said it will produce evidence implicating him in the attacks, which left more than 6,000 people dead or missing.
Washington has warned the Taliban to hand over bin Laden and his lieutenants, among other demands, or suffer the consequences. The Taliban on Sunday said they have been unable to find bin Laden and advise him of a recommendation to leave the country.
Meanwhile, in a statement faxed to news agencies, Omar said bin Laden's death would do little to remove the terrorist threat against the United States.
"If Americans want to eliminate terrorism, then they should withdraw their forces from the Gulf and they should put an end to the partial attitude on the issue of Palestine," Omar said.
Omar, who lives in the southern Afghan city of Kandahar, claimed the United States had "made Islam their hostage" and that it should avoid interfering in Muslim affairs.
"America wants to eliminate Islam and they are spreading lawlessness to install a pro-American government in Afghanistan," Omar said. "This effort will not solve the problem, and the Americans will burn themselves if they indulge in this kind of activity."
The brief statement appeared aimed not only at warning the United States against military action but also at encouraging other Muslim nations to distance themselves from Washington's efforts to build an international coalition to combat terrorism.
The Associated Press contributed to this report.