Crackdowns on illegal immigrants and other law enforcement efforts are driving gangs out of Northern Virginia and into Maryland and the District, a report released Monday concluded.

"Many gang members from Northern Virginia are moving or driving to Prince George's and other Maryland counties, into the District of Columbia or further south and west into Virginia to avoid dealing with police departments that are unrelenting in their efforts to keep gangs under control," authorities wrote in the Northern Virginia Regional Gang Task Force report.

The report said the task force's success is the result of Virginia law enforcement's use of anti-gang policing measures, including the referring of suspected illegal immigrants to federal authorities. Since the task force was created in 2003, it has arrested 952 gang members, more than 40 percent of whom were illegal immigrants, the report said.