Six foreign nationals with ties to violent southern California street gangs have been arrested over the past week, the latest in an ongoing operation that has netted 124 gang members total, the U.S. Immigration and Customs Enforcement announced.

Fifty-six foreign nationals are also now facing federal criminal charges, including drug offenses, firearms offenses and re-entry after deportation, a felony that carries a maximum sentence of 20 years in jail.

However, only 36 of those 56 are in custody. The other 20 remain at large and are actively being hunted.

They are linked to more than two dozen different street gangs, among them, MS-13, White Fence, the 18th Street Gang, the Black P-Stones, the Eastside Longos, the Villa Boys, and Los Primos

"The foreign national gang members we’re targeting are career criminals — brutal thugs who, in many cases, prey on members of their own immigrant community," said Julie L. Myers, Department of Homeland Security Assistant Secretary for ICE. "We want to send a clear message to these gang members: we will deal strongly with those who ignore our immigration laws and place our neighborhoods at risk."

Among those nabbed by agents during the past week was Pedro Barboza-Serrano, a 40-year-old Mexican and reputed member of the Eastside Longos.

Barboza-Serrano, whose criminal record includes prior convictions on drug charges, robbery, burglary, and spousal battery, pleaded not guilty Monday, and is scheduled to go on trial late next month.

The indictments of 56 today was part of an ongoing nationwide initiative in which the ICE is partnering with federal, state and local law enforcement agencies to address the threat posed by transnational gangs.

"As part of our long-standing battle against streets gangs and organized crime, we have utilized many tactics, including the filing of immigration charges," said Acting United States Attorney George S. Cardona. "This concerted law enforcement effort has led to dozens of criminal aliens being removed from the communities that have suffered so much as a result of gang activity."

Since the operation was launched in February 2005, ICE agents nationwide have arrested roughly 5,000 gang members and associates.

The U.S. Immigration and Customs Enforcement contributed to this report.