Iraqis living in the United States have played vital roles in the war on terror, contributing to the effort to thwart domestic terrorist attacks and aiding coalition forces taking part in Operation Iraqi Freedom, U.S. officials said Monday.

An FBI task force has wrapped up its wartime interviews with almost 11,000 Iraqis living in the United States and will resume its primary focus on combating terrorism now that the war in Iraq is winding down.

"These Iraqis who have tasted liberty here have longed for liberation in their native land," Attorney General John Ashcroft said during a press conference Thursday. "America is honored by their sacrifices and the risks they have endured to liberate Iraq."

"These efforts have clearly worked to make America safer," added FBI Director Robert Mueller.

The three goals of the task force were: to identify threats both at home and abroad from Iraqis within the United States from the interview process; to expel or arrest all known Iraqi intelligence officials in the United States, including those with diplomatic status; and to deal with counter-terrorism threats that may have increased during Operation Iraqi Freedom.

The interviews, which began on March 20, were conducted by hundreds of FBI agents and were part of a three-pronged mission of the Justice Department's Iraqi task force. The interviews focused on Iraqis who had ties to the former regime of Saddam Hussein and those who had recently traveled to Iraq.

While several dozen were detained for visa violations, no known terrorists or Iraqi spies were discovered in the interviews.

The interviews instead produced important information for U.S. forces, including locations of Iraqi bunkers, tunnel systems, manufacturing plants and military installations.

Mueller said the interviews generated around 250 reports, which were given to the U.S. military to assist them in their search for weapons production and storage facilities, bunkers, fiber-optic networks and Iraqi detention and interrogation facilities. Much of the information in the reports has been corroborated by forces overseas.

"The information was timely, excellent, relevant and greatly assisted in bridging gaps in other intelligence," Mueller said.

As a result of the Iraqi task force's effort, Ashcroft said, charges were brought against 21 people, including some who tried to cover up their illegal presence in the United States and others who attended terrorist training camps in Pakistan and Afghanistan.

"We will not tolerate those who would seek to do harm to our nation," Ashcroft warned, crediting a cooperative public and new investigative tools with anti-terrorism success. "We will continue to persist in our efforts."

About 25 FBI agents are also reviewing documents seized in Iraq to try to obtain additional information about further links to terrorism and any plans for future attacks, Mueller said. Some of the documents were seized from a compound controlled by an extremist Islamic group, he said.

The FBI also announced that it had sent agents to Iraq to assist in recovering antiquities stolen from museums by looters.

"We are firmly committed to doing whatever we can to secure these treasures to the people of Iraq," Mueller said. He said the agents would "assist with criminal investigations" and with the recovery of stolen items.

Mueller also said the FBI was cooperating with the international law enforcement organization Interpol in issuing alerts to all member nations to try to track any sales of the artifacts "on both the open and black markets."

Both officials noted that there have been no major terror attacks within the United States since Sept. 11, 2001, despite heightened concerns during the war with Iraq.

But "we know that a significant terrorist threat persists," Ashcroft said, adding that authorities would remain vigilant.

The Justice Department and FBI now can turn their focus on detecting would-be terrorists and preventing another terror attack by Al Qaeda or other extremist groups.

There are continued concerns about other forms of terror, including those from anti-government and right-wing extremists who could organize their own attacks.

In its latest bulletin to state and local law enforcement officials Thursday, the FBI noted that April 19 marks the tenth anniversary of the government raid on the Branch Dividian compound in Waco, Texas, in which nearly 80 people died as the compound burned to the ground.

The FBI bulletin, which goes to 18,000 law enforcement and government agencies, contains no specific threat because of the anniversary. But it does note that U.S. extremist groups have in the past used anniversaries such as Waco to stage terrorist attacks.

Timothy McVeigh chose the Waco anniversary to bomb the federal building in Oklahoma City in 1995, for example.

Fox News' Liza Porteus and The Associated Press contributed to this report.