Terror tape says 4,000 foreign fighters killed in Iraq

BAGHDAD, Iraq (CNN) -- A man identified as the leader of al Qaeda in Iraq said on an audiotape Thursday that more than 4,000 foreign fighters have died battling the U.S.-led coalition and Iraqi troops.
"We poured so much of our blood in Iraq," said the tape's speaker, purportedly new al Qaeda in Iraq chief Abu Hamza al-Muhajer.
CNN was unable to verify the speaker's identity. The tape, at 20 minutes, 31 seconds long, was posted on several Islamic Web sites Thursday.
The speaker urged other Muslims in Iraq to join the fight, saying he was launching a major military campaign.
"We are calling upon you to take your responsibilities because we are on crossroads, so don't fail us," the voice said, especially calling on Iraqi professionals such as chemists, physicists and nuclear experts to help.
Al-Muhajer, also known as Abu Ayyub al-Masri, is an Egyptian Islamic militant believed to be an expert in producing car bombs.
He succeeded Abu Musab al-Zarqawi, who died June 7 in a U.S. airstrike north of Baghdad.
The tape's speaker also pushed for the kidnapping of "Christian dogs" who could be exchanged for Omar Abdel-Rahman, an Egyptian Muslim cleric imprisoned since 1995 for conspiring to blow up landmarks in New York.