The U.S. government on Monday announced the arrests of 103 alleged members of MS-13 (search), a street gang rooted in Central America where members have been known to behead enemies and attack with grenades and machetes.

The arrests, in seven cities since early January, are the first of a nationwide crackdown on Mara Salvatrucha (search), or MS-13, which is one of the largest and most violent street gangs in the United States. Federal officials estimate between 8,000 and 10,000 MS-13 members live in 31 states — the majority of them in the country illegally. There have been machete attacks in eastern U.S. cities.

Agents with the U.S. Bureau of Immigration and Customs Enforcement (search) used information from state and local law enforcement authorities to target MS-13 activities in the New York, Washington, Los Angeles, Baltimore, Newark, Miami and Dallas metropolitan areas.

Half of the suspects charged in the sting, nicknamed "Operation Community Shield," have prior arrests or convictions for violent crimes, including murder, sodomy, assault and arson. All of them can be deported for violating immigration laws, said Homeland Security Assistant Secretary Michael J. Garcia.

"Our goal is simple: Operation Community Shield aims to dismantle the MS-13 criminal gang by removing gang members from the streets and from the community," said Garcia, director of ICE.

In Los Angeles on Sunday, agents arrested a man suspected of being a founding member and leader of the MS-13 cell in Hollywood who has previous robbery and weapons convictions. Last week, authorities also arrested the purported leader of the MS-13 cell in Long Branch, New Jersey, who had previous arson, weapons and grand larceny charges.

In Miami, where local officials arrested four more MS-13 suspects over the weekend, police set up surveillance operations to photograph or otherwise identify the gang members to check whether they are in the country illegally.

"We hit these areas where we know they are," said Miami-Dade Police Department Division Chief Willie B. Marshall. "Every single one that we've seen so far have some type of criminal background."

MS-13 began in El Salvador and now includes members from Ecuador, Guatemala, Honduras and Mexico.

Last month, former Homeland Security Deputy Secretary James Loy called MS-13 an emerging threat to the United States, referring to the gang and the al-Qaida terrorist organization in the same breath in testimony to Congress. Garcia said Monday that while there is no definitive link between MS-13 and al-Qaida, the gang's operations show that "you have to accept that as a homeland security risk as well."

Officials arrested 30 alleged gang members in the New York metropolitan area, the most of any of the seven cities targeted. Twenty-five were arrested in Washington, 17 in Los Angeles, and 10 each in the Baltimore, Newark and Miami areas. The last arrest came in Dallas, officials said.