By THOM SHANKER and STEVEN R. WEISMAN
WASHINGTON - Secretary of State Colin L. Powell and Defense Secretary Donald H. Rumsfeld have raised sharp complaints in recent days that Iran is providing support for the insurgency in Iraq, expressing concerns over what they say are Iran's attempt to shape Iraq's future.
Pentagon, State Department and military officials, describing intelligence reports that are fueling those concerns, say money, weapons and even a small number of fighters are flowing over the border from Iran to assist Shiite insurgents commanded by Moktada al-Sadr, a rebel cleric. But there is no consensus on the exact scale of Iranian activities.
Mr. Powell, in an interview with the editors of The Washington Times released by the State Department on Friday, said that Iran was "providing support" for the insurgency but that the extent of its influence was not clear. Most of the insurgency, he added, was "self-generating" and drawing support from indigenous sources.
Mr. Rumsfeld, speaking Tuesday during a visit to Fort Leonard Wood, Mo., said, "We have no doubt that the money comes in from Syria and Iran and undoubtedly other countries as well." He also cited reports that a shoulder-launched, antiaircraft missile had been smuggled into Iraq from Iran.
Bush administration officials, in addition to their charge that Iran is supporting the insurgency, described new concerns that Iran is financing medical clinics, hospitals and social welfare centers in Iraq, especially in areas where the interim government of Prime Minister Ayad Allawi and American forces are not in control.
"Now that these folks are starting to provide services that should be provided by the Iraqi government, their purpose is to provide a political base to extend Iran's influence in Iraq," one administration official said.
Such support is seen in Washington as akin to Iran's support for Hezbollah, the organization in Lebanon that runs social welfare centers and carries out attacks on Israel.
The extent of Iranian support for Iraqi insurgents has been debated within the administration since last spring, American officials said. While blaming outside support could be viewed as a convenient explanation for a tenacious insurgency, officials who spoke of the intelligence from Iraq made clear that the most serious threats to security there remained home-grown: Iraqis still loyal to Saddam Hussein, Iraqi Shiite militants and criminals, although the effects of foreign influence and foreign terrorists remain significant.
Administration and military officials say financial support from Iran is especially vital in allowing Mr. Sadr to challenge the new Iraqi leadership and the American military.
Mr. Sadr still can attract fighters from among the tens of thousands of disenfranchised, poor Shiite youths. But Pentagon and military officials say he has alienated the business class of Shiite moderates in southern Iraq, where the economy was disrupted by the fighting to dislodge his forces.
"He is not popular in Karbala and Najaf," said one senior military officer. So the money from Iran is critical in keeping Mr. Sadr's movement alive, officials say.
Weapons smuggled into Iraq from Iran are also a concern, but officials note that Iraq remains awash anyway in Baathist-era automatic rifles and domestic military ordnance.
In a new assessment of the changing face of the Iraqi insurgency, Pentagon and military officials now speak of what appears to be a small but worrisome alliance with Iraq's Sunni insurgents - mostly loyalists to Mr. Hussein's ousted government and Hussein-era military officers - who may be offering tactical combat training to the Sadr militia.
Senior military officers cite reports that a small number of Sunni insurgents have assisted Mr. Sadr's militia with explosives and sniper training.
Although the Sunni minority fears Shiite majority control of a unified Iraq, the new reports of cooperation indicate that the Sunni insurgency in a triangle of central and north-central Iraq is aided by Shiite fighters tying down thousands of American soldiers in the Najaf region.
"There are alliances of convenience," a partment official said.
Iraqi leaders, including Dr. Allawi and Defense Minister Hazim al-Shalaan, have contended in past public statements that Iran is providing weapons and material support to Mr. Sadr. Shiite clerics run Iran, and Shiites make up most of Iraq's population. But Dr. Allawi, asked in an interview with ABC News whether Iranians were causing trouble in Iraq, responded in a more tepid fashion.
"Well, we don't know," Dr. Allawi said, according to a transcript of the full interview provided by the ABC News program "This Week." "There are some people, some elements, who are coming and still are coming from Iran into Iraq." Dr. Allawi, who will travel to the United States this week in his first visit as acting prime minister, said the issue was of sufficient concern that he sent a deputy to meet with Iran's president and foreign minister.
For its part, Iran has denied accusations of interference in Iraq's affairs, repeatedly called for the withdrawal of all American-led forces from Iraq and officially invited Dr. Allawi to visit. Iran's official Islamic Republic News Agency, reporting Saturday on the arrival of Iraq's first ambassador to Iran since 1980, when the two countries began an eight-year war, said Dr. Allawi's visit would be a "positive step."
Some Bush administration officials remain skeptical of the extent of Iranian actions. Even Mr. Powell has noted that, while some limited support for Mr. Sadr is likely, Iran would not necessarily want to support a group like Mr. Sadr's, which also sees itself as a rival to Grand Ayatollah Ali al-Sistani, the most powerful Shiite cleric in Iraq. Mr. Sistani was born in Iran and has strong links to its clerical leaders.
"There are reasons for them to cooperate with one another and there are strong reasons why there is a limit to that cooperation," Mr. Powell said in the Washington Times interview.
Mr. Powell also said the administration was concerned about support for Iraqi insurgents from Syria. That concern was raised with Syrian leaders on a recent trip to Damascus by two administration officials, William J. Burns, assistant secretary of state for Near Eastern affairs, and Peter W. Rodman, assistant defense secretary for international security affairs.