Anti-FBI graffiti found in the prison cell of a man accused of playing a part in an alleged plot to attack soldiers on Fort Dix reinforce their contention that the man should remain in custody, authorities said in a legal filing Monday.

In the one-person cell where Agron Abdullahu is being held in the Federal Detention Center in Philadelphia, guards found two drawings.

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, which they say has links to some terrorist groups. Authorities said Abdullahu admitted to drawing the graffiti and explained that "Rainca" was the town where he was born.

The drawings, prosecutors say, are another reason Abdullahu should not be released from custody as he awaits trial.

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.

Abdullahu was arrested, along with five other men on May 7.

The other five were accused of conspiring to kill soldiers — a crime punishable by life in prison. Abdullahu, a 24-year-old baker who lived in Buena Vista Township, was charged with providing guns to illegal aliens, punishable by up to 10 years in prison.

Like three of the other suspects, he is an ethnic Albanian who was born in the former Yugoslavia.

He arrived in the United States as a teenager in 1999 after leaving war-torn Kosovo and being airlifted from neighboring Macedonia.

The federal public defender representing him, Lisa Evans Lewis, argued last month that he should be freed on bail because he has a responsibility to his parents and younger sisters and because he was not willing to go along with a plot to kill soldiers.

In an unusual move, Abdullahu himself testified at the bail hearing. At one point, he told the judge: "I would never do anything to harm this country."

Federal Magistrate Joel Schneider rejected those arguments, and tearful pleas from his family.

Schneider said he would rule on an appeal this week.

The government said the drawings found etched with the screw from a light switch plate onto the door of Abdullahu's cell were found more than a week after the initial denial of bail.

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.