From AP, :
ANKARA, Turkey (AP) — Islamic extremists have been moving supplies and new recruits from Iran into Iraq, say Iraqi Kurdish and Western officials, though it’s unclear whether Tehran is covertly backing them or whether militants are simply taking advantage of the porous border.
Iranian involvement with extremist groups in the Iraqi insurgency would be potentially explosive, especially given the history of U.S.-Iranian animosity. Defense Secretary Donald H. Rumsfeld said recently Iran was engaged in “a lot of meddling” in Iraq but gave no details.
Iran, which shares a mountainous 800-mile border with Iraq, has confirmed that loyalists of the al-Qaida-linked Ansar al-Islam group illegally entered Iran from Afghanistan after the start of the U.S.-led 2001 war to oust the Taliban and destroy Osama bin Laden’s terrorist training camps. But Iran’s government has repeatedly denied it is backing the radicals.
A handful of senior al-Qaida operatives who were among those fleeing to Iran after the Afghanistan war may have developed a working relationship with the Revolutionary Guards, a special military unit in Iran linked to Tehran’s hard-liners, U.S. counterterrorism officials have said.
The U.S. government report on the Sept. 11, 2001 attacks also pointed to contacts between Iranian security officials and senior al-Qaida figures and found evidence that eight to 10 of the Sept. 11 hijackers passed through Iranian territory. There was, however, no evidence the Iranians knew that the hijackers were planning to attack the World Trade Center.
Iraqi officials have suggested privately that Iran, which is overwhelmingly Shiite Muslim, is backing its Shiite brethren, who form a slight majority in Iraq. One Iraqi official said more than 100 volunteer fighters have entered this year from Iran into southern Iraq, where Iran may be trying to use its influence within the dominant Shiite community there.
Iran might also support extremists from the rival Sunni branch of Islam – such as al-Qaida or the group loyal to Jordanian terrorist Abu Musab al-Zarqawi – to gain influence in the Sunni community, which is powerful in central Iraq, and to destabilize U.S. efforts to control the country, some analysts say.