(Recasts with suspects detained)

By Jon Hurdle

CAMDEN, New Jersey, May 8 (Reuters) - Six suspected Islamic radicals were detained on Tuesday on charges of plotting to attack the U.S. army base at Fort Dix in New Jersey with rocket-propelled grenades and automatic weapons.

The group, which is not believed to have links to any foreign organizations, had amassed semi-automatic assault rifles, shotguns and handguns while trying to acquire the more sophisticated weaponry, federal authorities said.

The men, aged 22 to 28, included three brothers born in the former Yugoslavia who ran a roofing business. One Jordanian-born suspect was a Philadelphia taxi driver and a Turkish-born man worked as a convenience store clerk.

The suspects conducted surveillance of Fort Dix and other U.S. military installations in New Jersey, Delaware and Pennsylvania, plotting attacks inspired by an international call for holy war against the West, officials said.

They settled on Fort Dix as a target because one suspect knew it well from a previous job delivering pizza to the base, U.S. Attorney Christopher Christie told a news conference, citing evidence from two FBI informants who infiltrated the group.

"Today we dodged a bullet," said Jody Weis, the FBI agent in charge of the Philadelphia field office. "What we are witnessing here is kind of a brand new form of terrorism."

The suspects were identified as Eljvir, Dritan and Shain Duka, three Yugoslav-born brothers who were illegal aliens; Turkish-born U.S. resident Serdar Tatar; Yugoslav-born U.S. resident Agron Abdullahu; and Mohamad Shnewer, a U.S. citizen born in Jordan.

"My intent is to hit a heavy concentration of American soldiers, light up four or five Humvees full of soldiers," Christie quoted one of the suspects as saying.

They also discussed attacking two U.S. warships when they docked in Philadelphia and staging an attack on the annual Army-Navy college football game, prosecutors said.

VIDEO SET OFF INVESTIGATION

Media in Serbia's U.N.-run Kosovo province reported four of the six men were ethnic Albanians, either from Macedonia, Montenegro or Kosovo itself.

The Islamic Community in Kosovo issued a statement saying it was "shocked" at news of the plot.

"This case is particularly hard for us, knowing that people of our nation and our religion are involved," it said.

The arrests were made on Monday night in Cherry Hill, New Jersey, a Philadelphia suburb where the Duka brothers live.

U.S. Magistrate Judge Joel Schneider ordered the men detained to face charges of plotting to kill military personnel and weapons possession. Each wore a prison jumpsuit and was shackled at the ankles.

Sixteen family members including women wearing headscarves sat in the public benches. Some wept quietly.

A separate hearing to determine whether the suspects would be granted bail was set for Friday.

Fort Dix, about 40 miles (60 km) east of Philadelphia, is used to train reservists from all branches of the military, many of whom are preparing for Iraq and Afghanistan.

The investigation began in January 2006 when a retailer alerted police about a customer who had asked to copy a video onto a DVD.

The footage depicted young men shooting assault weapons at a firing range while calling for "jihad" and shouting "Allah-o-Akbar" -- "God is Greatest" -- in Arabic, prosecutors said in a criminal complaint.

By March 2006, the group was infiltrated by the first of two FBI informants, who obtained computer files. One of these -- a file named "19" -- appears to be the wills of at least two of the 19 hijackers who carried out the Sept. 11 attacks.

Another contained images of Osama bin Laden urging viewers to join their movement.

The suspects allegedly trained in Pennsylvania's Pocono mountains in February, where law enforcement officials conducted video surveillance. (With reporting by Fatos Bytyci in Pristina)

AlertNet news is provided by