Three of their sons are in prison, serving life sentences for conspiring to attack Fort Dix. But one day, Ferik and Zurata Duka believe, their children will be free.

The Cherry Hill couple were among about 30 people outside the federal courthouse in Center City on Tuesday, holding placards and chanting to protest the alleged injustice done to the Muslim men, all in their 20s, known as the "Fort Dix Five."

The Duka brothers - Dritan, Shain, and Eljvir - and two others, Mohamad Shnewer and Serdar Tatar, were convicted in December 2008 of conspiring to kill Fort Dix soldiers after two informants testified that they infiltrated the group of suspected jihadists at the direction of federal authorities and recorded hundreds of hours of conversations.

The FBI pursued the case as part of its policy of preemptive prosecutions of persons they believed to be terrorists. Lawyers for the five men, who maintain their innocence, are preparing to appeal the convictions.

The protesters said the men were among of hundreds of innocent Muslims targeted by federal authorities who have manipulated evidence to secure convictions and unusually harsh sentences.

"We have an avalanche of cases throughout the United States," said Mauri Saalakhan of the Peace Thru Justice Foundation, a Washington-based organization that has followed the prosecution of Muslims across the country and is pushing the Obama administration to conduct a national review of the cases.

The "Fort Dix Five" romanticized jihad and their boasts were "admittedly, at times, irresponsible," Saalakhan said, but they never intended to take action.

The men, all foreign-born and raised in Cherry Hill, were arrested in May 2007 after Dritan and Shain Duka tried to buy machine guns from one of the informants, Mahmoud Omar. Shnewer allegedly provided a Fort Dix map.

His sons never talked of killing Americans, Ferik Duka said; they were friends with Omar and bought guns for recreational shooting at a range in the Poconos. The government, he said, paid the informants to trap his sons.

"America is the leader of freedom and democracy. If there is any justice, they will get out," Duka said as he stood in the 600 block of Market Street. "Many others are in jail simply because they are Muslim."

Some of Dritan Duka's five children, ages 5 through 12, led the group in chants.

"My father and uncles are facing life in prison, plus 30 years," Lejla Duka, 12, read from a statement. "They were all arrested because they are devout Muslims."

Shnewer went to college and worked hard, said his mother.

"He's not a criminal," Faten Shnewer said. He will be freed, she said, because "we're right."

The protesters included members of Project SALAM, which also tracks prosecutions of Muslims. Lawyer Stephen Downs, of Albany, N.Y., is a volunteer with the group who represented a Muslim client found guilty in New York. The conviction of the "Fort Dix Five" was an "egregious" miscarriage of justice, he said.

"This is nothing more than out-and-out entrapment," Downs said.

Acting U.S. Attorney Ralph Marra last year called the life sentences appropriate punishments for "dangerous men" willing to kill for political motivations.

In recorded conversations, played throughout the eight-week trial, the men talked of striking back at the United States and voiced frustration at the plight of Muslims worldwide.

Federal authorities began investigating the men in January 2006 after a Circuit City clerk turned over a videotape, which was dropped off at his store for duplication, that showed the group riding horses, shooting guns at a firing range, and calling out, "Allahu akbar," or "God is great."

Omar and Besnik Bakalli were paid by the FBI to seduce them the men into making incriminating statements, the protesters said. The group members handed out literature calling them "provocateurs" who had snared impressionable men in return for money and, in one case, avoiding deportation.

Omar and Bakalli "used money and manipulation to build up [the defendants'] interest in the jihad," according to the literature. "They watched jihadist videos with the young men, taunted the men on their lack of resolve to take action [against the United States], and followed them around with hidden video cameras and devices to record every word spoken in passion or anger."

Contact staff writer Barbara Boyer at 856-779-3838 or bboyer@phillynews.com.