Updated

Al Qaeda's No. 2 Ayman al-Zawahri harshly criticized Libyan leader Moammar Gadhafi in a new audio tape Saturday, accusing him of being an enemy of Islam and threatening a wave of attacks against the North African country because it improved relations with the United States.

In the 28-minute audiotape called "Unity of the Ranks," al-Zawahri also announced that the Libyan Islamic Fighting Group was joining ranks with Al Qaeda.

"The Islamic nation is witnessing a blessed step ... The brothers are escalating the confrontation against the enemies of Islam: Gadhafi and his masters, the Washington crusaders," al-Zawahri said in the audiotape. The recording could not be independently verified, but it appeared on a Web site commonly used by insurgents and carried the logo of Al Qaeda's media production house, as-Sahab.

The recording also carried a message Abu Laith al-Libi, a Libyan Al Qaeda commander in Afghanistan who accused Gadhafi of decades of tyranny.

"He is the tyranny of Libya and is dragging the country to the swamp," al-Libi said in the recording that also featured old video footage of him walking with other masked gunmen.

"After long years, he (Gadhafi) discovered suddenly that America is not an enemy ... and is turning Libya into another crusader base," said al-Libi, who has appeared in several recent Internet Al Qaeda videos.

For decades, the U.S. had regarded Libya as a pariah state after Gadhafi came to power in a military coup in 1969 and turned against the West.

Libya was demonized for sponsoring various terrorist groups and for trying to undermine pro-Western governments in Africa. Washington put Libya on a list of state sponsors of terrorism and imposed sanctions that barred American companies from doing business in the oil-rich country. In 1986, U.S. warplanes carried out airstrikes against Libya.

But the tide started to turn in 2003, after Gadhafi's surprise decision to dismantle Libya's clandestine nuclear program. That same year, Libya reached a $2.7 billion settlement with families of the victims of the 1988 Pan Am bombing over Lockerbie, Scotland, and the next year it paid $170 million compensation to the families of the 170 victims of the 1989 bombing of a French UTA passenger jet.

The United States resumed full diplomatic relations with Libya last year and removed Libya from the State Department's list of terrorism sponsors.

The State Department also has praised Libya's cooperation in helping the U.S. in the search for Al Qaeda and other terror suspects in the Middle East and North Africa.

In the audio recording, al-Zawahri also calls on followers to defeat other North African leaders including Tunisian President Zine El Abidine Ben Ali, Moroccan King Mohammed VI and Algerian President Abdelaziz Bouteflika — as well as Gadhafi.

"Tell the dogs of Gadhafi, the agents of the international crusaders, our brothers will confront your evil," he said.