Six foreign nationals described by the FBI as Islamic militants were arrested on charges they plotted to carry out a suicide attack on a U.S. army base in New Jersey and "kill as many soldiers as possible," U.S. authorities said Tuesday.

The alleged plan to kill U.S. servicemen at Fort Dix was stopped in the initial stages after investigators infiltrated the group with an informant well over a year ago and secretly recorded the defendants, U.S. attorney Christopher Christie said.

There were no signs the group was directly connected to international terror groups such as al-Qaeda, but were "clearly inspired" by the international jihadist movement, Christie said. 

"This is a new kind of terrorism," Christie told reporters Tuesday. "This is what law enforcement is supposed to do in the post-9/11 era — stay one step ahead."

The FBI was alerted to the group in early 2006 after an individual took a video to a store to be duplicated into DVD format, FBI special agent Jodi Weis said.

The video allegedly showed 10 men, including the six arrested, shooting assault weapons in militia style and calling for jihad, or holy war.

"That's why we're here today — because of the courage and heroism of that individual," Weis said, in reference to the clerk.

The six were scheduled to appear in U.S. District Court in Camden later in the day to face charges of conspiracy to kill U.S. servicemen, said Michael Drewniak, a spokesman for the U.S. Attorney's Office in New Jersey.

Officials said four of the men were born in the former Yugoslavia, one in Jordan, and one in Turkey. Five of them lived in Cherry Hill, about 16 kilometres east of Philadelphia and 32 kilometres southwest of Fort Dix, Drewniak said.

"They were planning an attack on Fort Dix in which they would kill as many soldiers as possible," he said.

The men were arrested on Monday while trying to buy automatic weapons in a sale set up by law-enforcement authorities. 

"Today we dodged a bullet," the FBI's Weis said. "And looking at the weapons they were trying to obtain, we dodged a lot of bullets."

A criminal complaint filed by the FBI alleges the men attempted to buy AK-47 assault rifles and maps of the base from an arms dealer who was secretly co-operating with the law enforcement agency.

The group also allegedly discussed the need to obtain "something else" other than machine-guns and talked about bomb-making material, including C-4 and nitroglycerin.

"If you want to do anything here, there is Fort Dix and I don't want to exaggerate, and I assure you that you can hit an American base very easily," suspect Mohamad Ibrahim Shnewer allegedly said in a conversation, one of several secretly recorded by an FBI informant over the past year.

Group sought fatwa for mission, documents allege

The complaint also alleges one of the men discussed the need to obtain a fatwa, or Islamic ruling, approving the mission before they attacked the base.

The complaint also alleges the men trained for the attack in the Poconos, and allegedly conducted surveillance at other area military institutions, including the army's Fort Monmouth, Dover Air Force Base in Delaware and the U.S. Coast Guard Building in Philadelphia.

"It doesn't matter to me, whether I get locked up, arrested or get taken away, it doesn't matter. Or I die, doesn't matter, I'm doing it in the name of Allah," the complaint alleges one of the suspects told the informant.

The group also allegedly used a laptop to watch video footage of insurgent attacks on U.S. forces in Iraq. At one point, according to the informant, the men allegedly laughed when one of them pointed out a marine's arm being blown off in an attack.

"These are the type of people that we were dealing with in this investigation," Christie told reporters.

Court papers identified the men as: 

• Shnewer.
• Dritan Duka.
• Eljvir Duka.
• Shain Duka.
• Serdar Tatar.
• Agron Abdullahu.

The Associated Press reported checks with Immigration and Customs Enforcement show that the Dukas are illegally living in the United States, according to FBI complaints unsealed with their arrests. One of the suspects worked as a delivery man at the nearby pizza restaurant and often took food to the base, investigators said.

Base trains soldiers for Iraq and Afghanistan

Fort Dix is used to train soldiers, particularly reservists. It also housed refugees from Kosovo in 1999.

Jeff Sagnip, a spokesman for U.S. Rep. James Saxton, who represents Fort Dix, said the base, along with adjacent McGuire Air Force Base, has been put on its highest security alert level.

He said Fort Dix typically has 15,000 people, including 3,000 soldiers. McGuire, which is adjacent to Fort Dix, has about 11,500 people.

Soldiers at Fort Dix have been training for warfare in Iraq and Afghanistan, Sagnip said.