June 18, 2007 7:23 PM

MOUNT LAUREL, New Jersey-Anti-FBI graffiti found in the prison cell of a man accused of aiding in an plot to attack soldiers at a military base in New Jersey adds further proof that the defendant is a risk and should remain in custody until his trial, authorities said in a legal filing Monday.

Guards found two drawings in the one-person cell where Agron Abdullahu is being held in the Federal Detention Center in Philadelphia. One had the letters "FBI" with a drawing of a gun pointing to them. The other had the phrase "Rainca Kosava UCK," which federal prosecutors say refers to the Kosovo Liberation Army, the guerrilla force that also fought Serb troops during Kosovo's 1998-1999 war.

Authorities said Abdullahu admitted to drawing the graffiti and explained that "Rainca" was the town where he was born.

The drawings were found more than a week after Abdullahu, who is charged with providing weapons to illegal immigrants, was denied bail. He is one of six foreign-born Muslims who authorities clain planned to attack soldiers at Fort Dix.

The plot was foiled when an electronics store clerk notified authorities about a video the men allegedly brought in to the store to be converted into a DVD.

All six were arrested May 7. The five other defendants, who include a Jordanian and a Turk, are charged with conspiring to kill military personnel, charges punishable by life in prison.

Abdullahu's attorney has been trying to have him released on bail pending his trial, arguing he must take care of his parents and younger sisters. His lawyer says Abdullahu, who like three others charged is an ethnic Albanian born in the former Yugoslavia, is not a risk because he was not willing to go along with a plot to kill soldiers.

Prosecutors, however, point to the drawing as another reason why he should not be released from custody.

In a court filing, the U.S. Attorney's Office said Abdullahu seemed to be thinking about "seeking revenge against the FBI agents who caused him to be imprisoned in the first place."

"Releasing Abdullahu now would not only endanger the community at large, but also the agents who investigated this case," prosecutors wrote.

Authorities said the drawings were found more than a week after the initial denial of bail.

Abdullahu's public defender, Lisa Evans Lewis, who generally does not speak to reporters, did not return an after-hours call to her office. Greg Reinert, a spokesman for the U.S. Attorney's Office, said his office would not elaborate on the government filing.

U.S. District Judge Robert Kugler has said he hopes to try the case in October.