A voice claiming to be the new Al Qaeda in Iraq leader called for scientists to join the jihad and demanded foreigners be taken hostage during Ramadan in an audiotape posted Thursday to an Islamic Web site.
Nuclear scientists and explosives experts were invited Thursday to test their experimental weapons on U.S. military bases in Iraq and to join the jihad against the West by the voice, who identified himself as Abu Hamza al-Muhajir — also known as Abu Ayyub al-Masri — the leader of Al Qaeda in Iraq.
"The field of jihad (holy war) can satisfy your scientific ambitions, and the large American bases (in Iraq) are good places to test your unconventional weapons, whether biological or dirty, as they call them," said al-Muhajir. The voice could not be independently identified.
Al-Muhajir also called on jihadists to take foreigners hostage during Ramadan so they can be used as bargaining tools to win the release of Egyptian cleric Omar Abdel Rahman, who is jailed in the United States on charges linked to the 1993 bombing of the World Trade Center in New York City.
"I appeal to every holy warrior in the land of Iraq to exert all efforts in this holy month so that God may enable us to capture some of the Western dogs to swap them with our sheik and get him out of his dark prison," the voice said.
Ramadan began last weekend across the Muslim world.
Al-Muhajir said more than 4,000 foreign insurgents have been killed in Iraq since the U.S.-led invasion in 2003, which is the first known statement from insurgents in Iraq about their losses. It was unclear why the group would advertise its losses, but martyrdom is revered among Islamic fundamentalists, and could be used as a recruiting tool.
"The blood has been spilled in Iraq of more than 4,000 foreigners who came to fight," said al-Muhajir.
The Arabic word he used indicated he was speaking about foreigners who joined the insurgency in Iraq, not coalition troops.
The speech was entitled "Come to a word that is just between you and me," according to a translation done by the SITE Institute.
Al-Masri is believed to have succeeded Abu Musab al-Zarqawi, who died in a U.S. airstrike north of Baghdad in June.
On the 20-minute tape, he called for experts in the fields of "chemistry, physics, electronics, media and all other sciences — especially nuclear scientists and explosives experts" to join his group's holy war against the West.
Al-Masri also issued an amnesty to Iraqis who cooperated with their country's "occupiers," calling on them to "return to your religion and nation" during the Muslim holy month of Ramadan.
"We will not attack you as long as you declare your true repentance in front of your tribe and relatives... and put your hands in the hands of your holy warrior brothers and sons in order for security to be restored in our land," he said. "The amnesty ends by the end of this holy month."
Al-Masri last appeared in a Web video last week, which apparently showed him executing a Turkish hostage in Iraq. It was first released in 2004, when Zarqawi headed the group, but it was reissued last week. It was believed to be the first of al-Masri released since he took control of the militant group.
The audio recording appeared on a Web site that frequently airs Al Qaeda tapes and messages. A banner was posted there Wednesday warning that Al Qaeda No. 2 Ayman al-Zawahiri would soon release a new message about the pope, President Bush and Sudan's troubled Darfur region. It did not specify whether the upcoming message would be a video, audiotape or text, but al-Zawahiri usually releases videos.
FOX News' David Piper and the Associated Press contributed to this report.