News agency receives purported bin Laden message

Bin Laden's signature from a verified source, left, and from a letter sent Monday, right.

KABUL, Afghanistan (CNN) -- Suspected terrorist Osama bin Laden apparently sent a letter Monday expressing sorrow over the deaths of three people killed last week in anti-U.S. demonstrations in Karachi, Pakistan.

The letter was delivered to the Qatari-based news channel Al Jazeera at its offices in Kabul.

Al Jazeera officials said based on previous transmission they have received from bin Laden, they believe the letter is authentic. Whether it was actually from bin Laden could not be independently verified.

The Taliban rulers of Afghanistan have said they have cut bin Laden off from communicating with the outside world. However, over the weekend, they said they had lost track of where bin Laden is.

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The English translation of the text is as follows:

"To our Muslim brothers in Pakistan, peace be upon you.

"The news of the death of our brother Muslims in Karachi while expressing their opposition to the crusade of American forces and their allies on Muslim lands Pakistan and Afghanistan has reached us with great sorrow.

"We ask God to accept them as martyrs and to join them with the prophets, the caliphs and the martyrs and those of goodwill and to provide for their families. Those who are left behind children are my children and I will, God willing, take care of them.

"It's not a surprise that the Muslim nation in Pakistan will die defending Islam. It is considered on the front line of defending Islam. As Afghanistan was on the front line of defending itself and Pakistan during the Russian invasion more than 20 years ago.

"We hope that these brothers will be the first martyrs in the battle of Islam in this era against the new Jewish and Christian crusader campaign that is led by the Chief Crusader Bush under the banner of the cross.

"We tell our Muslim brothers in Pakistan to use all their means to resist the invasion of the American crusader forces in Pakistan and Afghanistan.

"I convey to you good news my beloved brothers that we are steadfast in the way of jihad following in the footsteps of the prophet -- peace be upon him -- with the believing heroes, the people of Afghanistan and under the leadership of our prince the warrior Mullah Mohammed Omar.

Osama bin Laden

"We ask God to make us defeat the infidels and the oppressors and to crush the new Jewish-Christian crusader campaign on the land of Pakistan and Afghanistan.

"If God allows you to win, there will be no defeat; if he chooses that you will be defeated nothing will allow you to win. Therefore, depend on God.

"Your brother in Islam, (signed) Osama bin Muhammed bin-Laden"

Separately, Taliban supreme leader Mullah Mohammed Omar said Monday the United States cannot get out of the current crisis by killing him or bin Laden.

Omar said the United States needs to remove its military from the Persian Gulf, stop its involvement in the "Palestinian crisis," and "leave Islam alone and so Islam can be expressed freely. And do not get involved in Islamic or Muslim affairs."

The letter, written in Arabic, was hand-delivered to Al Jazeera and other news organizations.

At a news conference in Islamabad, the Taliban ambassador said the Taliban government was mobilizing hundreds of thousands of men to help ward off any attack staged by the United States.

"In view of the current conditions, 300,000 well-experienced and equipped men have been stationed in the center (of the country), at borders and other significant areas, in addition to its former detachments," Taliban Defense Minister Mullah Obaidullah said in a statement read by the Taliban ambassador to Pakistan Mullah Abdul Salam Zaeef.

"All detachments of the national defense ministry are ready for the defense of their religion and country with full vigor and order."

In the past, Taliban officials have talked of a force between 30,000 and 50,000 in battling the Northern Alliance, the leading opposition group.

Tribal leaders said the reference to a force of 300,000 reflects the belief that men, not currently involved in the armed battled against the Northern Alliance, are being called into service.

Zaeef repeated that Omar had accepted the recommendation of Muslim clerics that bin Laden be asked to leave Afghanistan of his own accord.