IRAQ - Oct 8 - Qaeda No. 2 Warns His Chief In Iraq.

The second-ranking leader of Al Qaeda Ayman al-Zawahiri warns Abu Musab al-Zarqawi, the top militant in Iraq that attacks on civilians and videotaped executions committed by his followers threaten to jeopardise the broader extremist cause. The warning, was in a 6,000-word letter, dated early in July, that was obtained by US forces conducting counterterrorism operations in Iraq, the official said in a briefing. Zawahiri said that Iraq had become "the place for the greatest battle of Islam in this era" but that Zarqawi's forces should keep in mind that it was only a stepping stone toward a broader victory for militant Islam across the Middle East. "The mujahedeen must not have their mission end with the expulsion of the Americans from Iraq, and then lay down their weapons, and silence the fighting zeal", Zawahiri said in the letter, according to a partial translation provided by the official, who declined to provide verbatim translations of anything more than three sentences from the document. Under the ground rules for the briefing, the official cannot be identified. The official said Zawahiri had also warned that Zarqawi's forces should concentrate their attacks on Americans rather than on Iraqi civilians, and should refrain from the kind of gruesome beheadings and other executions that have been posted on Al Qaeda Web sites. The American official would not say when or how US forces obtained the communication, or whether it was in electronic or printed form. But the official said he had "the highest confidence of its authenticity", which he said had been verified by "multiple sources over an extended period of time".