A message broadcast Sunday by Arab satellite television stations was attributed to al-Qaida's second-ranking leader, Ayman al-Zawahri. The speaker urged Pakistanis to overthrow President Pervez Musharraf. He said the Pakistani leader has betrayed Islam by helping the United States topple the Taleban regime in neighboring Afghanistan.

But Pakistan Foreign Ministry spokesman Masood Khan told reporters in Islamabad, his country will not be deterred by such threats. "Al-Qaida is a terrorist organization. Pakistan is part of the war on terrorism and our pursuit of terrorists, al-Qaida and there associates will continue despite these threats. We [will] not be deterred," he said.

In the message, the speaker says Muslims in Pakistan must unite to remove President Musharraf, calling him a traitor. The speaker urges the Pakistanis to put in place a loyal leadership in Pakistan that defends Islam and Muslims. He accuses President Musharraf of planning to send his troops to Iraq to be killed instead of American soldiers.

The identity of the speaker on the audio tape or the authenticity of the tape has not been verified.

But Pakistani spokesman Masood Khan rejected the charges, saying that President Musharraf is fighting for the Muslim world and, in his words, has become the symbol of Muslim unity. "[Mr. Musharraf] is a bridge between the Islamic world and the West. All the allegations that have been made by al-Qaida allegedly, are misplaced and are deliberately designed to mislead the people of Pakistan and the Islamic world and we reject them," he said.

The Pakistani spokesman said such statements do pose a threat to his country, but he said it is prepared to meet any challenge. "These shady characters from time-to-time, al-Qaida leaders, I do not know whether they are speaking on their behalf or their proxies speak on their behalf, they issue such threats to Pakistan and the to the head of the a sovereign state. This is outrageous. But we are alert and are fully capable of meeting any challenge," he said.