Gang violence became synonymous with urban crime in the 1990s, and while it looked like a problem the nation had regained control of, a new study suggests that gangs are making a comeback.

Fox News obtained a preview of the annual National Youth Gang Center's (search) survey for 2002, funded by the Department of Justice. The report showed that after five years of steady decline, gang activity was up 2 to 3 percent nationwide last year — with the biggest jump in cities of under 50,000 people and in suburban areas.

"Sometime in late 2001-2002, the gang problem started kicking up again in this country," said John Moore, director of the National Youth Gang Center.

Even more troubling: Of the more than 15,000 law enforcement agencies surveyed, 42 percent said they believed the problem was getting worse.

"It takes a while for a community to realize they have a gang problem, and even after they realize it, it takes a while to acknowledge it and want to do something about it," said James Howell, a National Youth Gang Center criminologist.

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Some graffiti found in South River, N.J., was the first warning police there had of renewed gang activity. The notorious 18th Street Gang (search) was trying to move into the town of 15,000 and recruit from the area's community of Hispanic immigrants.

"They don't have any contact with the police department at all," Lt. John Bouthilette of the South River Police Department (search) said of the illegal immigrant population. "They don't want to be known, so if something violent happens, we are not the first people they turn to."

Analysts say situations like the one in South River should be a red flag for law enforcement, which comes at a time when police in cities and towns are already stretched thin with new homeland security demands.

"The squeaky wheel has been terrorism and security duties, so we've seen a lot of reductions in gang units," said Moore.

Despite such challenges, some local departments have reigned in the problem of gang violence — but that doesn't mean it's gone for good.

South River Police Sgt. John Casey's squad successfully identified the 18th Street Gang and pushed it out of town. But every night, he watches for signs of its return.

"We look for the people, the tattoos, the colors," Casey said. "You have to constantly stay on top of it because it changes every week."

Catherine Herridge is an award-winning Chief Intelligence correspondent for FOX News Channel (FNC) based in Washington, D.C. She covers intelligence, the Justice Department and the Department of Homeland Security. Herridge joined FNC in 1996 as a London-based correspondent.