A Maryland school located in a sanctuary county needed extra security on campus this week after being threatened with “retaliation” by the violent El Salvador-based MS-13 Gang, according to officials.

The Albert Einstein High School in Montgomery County, Maryland — a sanctuary county that shields illegal alien criminals from deportation — was forced to increase security this week after authorities said the violent MS-13 Gang made credible threats of “retaliation.”

Police said the retaliation threat by MS-13 gang members was in relation to an incident last week, though they would not provide details on the incident.

Acting United States Citizenship and Immigration Services (USCIS) Director Ken Cuccinelli hinted that the MS-13 Gang threat at the sanctuary county high school was almost certainly linked to illegal immigration.

Anyone think illegal immigration has anything to do with this??? https://t.co/KAdO38GYfg — USCIS Acting Director Ken Cuccinelli (@USCISCuccinelli) October 30, 2019

Montgomery County has been plagued with illegal alien crime in recent months. As Breitbart News has reported, a total of nine illegal aliens were arrested and charged with sex crimes — some against children — over the course of just two months. The most recent case included the arrest of a 23-year-old illegal alien who was charged with raping an intoxicated woman.

In King County, Washington — another sanctuary county — two illegal alien MS-13 gang members were charged with murdering 16-year-old Juan Carlos Con Guzman by brutally hacking his body into pieces.

The MS-13 Gang, originally from El Salvador, is primarily made up of illegal aliens, Unaccompanied Alien Children (UACs), and newly arrived immigrants living in the U.S. Today, the gang operates largely in Los Angeles, New York, Virginia, and Washington, D.C., but conducts gang activities and drug distribution across at least 40 states, and has at least 10,000 members in the country.

Investigations by the Justice Department have revealed that MS-13 Gang leaders in El Salvador have sent recruits and members to the U.S. illegally, often posing as UACs, to help strengthen ranks within the gang.

John Binder is a reporter for Breitbart News. Follow him on Twitter at @JxhnBinder.