The Islamic State group is in possession of at least one passport-printing machine and "boxes of blank passports," according to a U.S. intelligence report which warns that the terror group might have already infiltrated American borders using the authentic-looking passports, reported ABC News.

The 17-page Homeland Security Investigations Intelligence Report, issued to law enforcement last week, says the Islamic State group (ISIS) likely obtained the blank passports and specialized mobile printing machine when it took over the eastern Syrian city of Deir ez-Zour last summer, which was home to a passport office. The Islamic State group's de facto capital of Raqqa had another passport office.

"Since more than 17 months [have] passed since Raqqa and Deir ez-Zour fell to ISIS, it is possible that individuals from Syria with passports 'issued' in these ISIS controlled cities or who had passport blanks, may have traveled to the U.S.," the report says, rating the primary source of the information at "moderate confidence," which is the second-highest given for source assessments, according to ABC News.

The information was first made public on Wednesday by FBI Director James Comey while he testified before the Senate Judiciary Committee.

"The intelligence community is concerned that they [IS] have the ability, the capability to manufacture fraudulent passports, which is a concern in any setting," Comey told the legislators, according to The International Business Times.

Comey added that the bureau "doesn't have reason to believe" that ISIS has already established terrorist cells inside the U.S. "They are trying to do two things: They are trying to motivate people already in the United States to become killers on their behalf. They would very much like to as they aspire to be the leader in the global jihad, send people here to conduct attacks. It's that second piece that we have not seen yet," Comey said, according to the National Enquirer.

John Cohen, a former Department of Homeland Security intelligence official, told ABC News that "if ISIS has been able to acquire legitimate passports or machines that create legitimate passports, this would represent a major security risk in the United States."

The issue of fake Syrian passports has been under the spotlight since shortly after the Nov. 13 Paris terrorist attacks, when European authorities discovered that two of the suicide bombers, thought to be ISIS members, had disguised themselves as Syrian refugees fleeing the civil war and entered Europe with fake passports.

U.S. lawmakers are concerned that President Obama's Syrian refugee resettlement plan, which will bring 10,000 Syrians to America over the next year, could be exploited by the Islamic State group in a similar fashion.