Investigators warned 3 years ago about possible al-Shabaab attacks

CHICAGO (WLS) -- The Mall of America in Minneapolis may have gotten a threatening shout out by al-Shabaab - but terrorists have "help wanted" signs out in Chicago and throughout the Midwest. So much so that federal investigators warned nearly three years ago of potential attacks in the US by supporters of the Somalian terror group.

Videos of al-Shabaab fighters in Somalia and the supposed camaraderie that American recruits would experience by joining, have concerned federal law enforcement since the terror group began targeting Midwestern men in 2007.

This video that identified Mall of America as a potential target did not come as a surprise to U.S. intelligence agents because thousands of Somalian nationals have settled in the Twin Cities.

Nor did the identification of Westfield group that operates three malls in metro Chicago, as Chicago is considered a primary center for al-Shabaab's efforts to radicalize young Muslim men.

A 2011 House Homeland Security investigation found the US is a "primary exporter of fighters to al-Shabaab" for their participation in "suicide bombings, propaganda and recruiting tapes."

At that time the report cited 38 al-Shabaab cases prosecuted in Illinois, Minnesota, Ohio, California, New Jersey, New York, Missouri, Alabama, Virginia and Texas, and the "danger of attacks inside the U.S. Homeland."

A threat that Illinois Sen. Dick Durbin says still exists.

"What did we hear over the weekend about some intelligence that extreme groups may be attacking America's major malls and shopping centers? It's a reminder - we are constantly vulnerable in a dangerous world," Durbin said. "Let's not play Russian roulette when it comes to the funding of an important department like the Homeland Security Department."

Dozens of Americans have come to Somalia to train and fight with al-Shabaab, according to federal authorities. At least 15 U.S. converts were killed during overseas fighting for al-Shabaab over the past several years. Among the recruits: this Chicago man, Shaker Masri - now serving a 10-year sentence for a planned suicide attack on soldiers.

Al-shabaab is an offshoot of Al Qaeda, and the group does have experience in attacking shopping malls. A year and a half ago in Kenya, a small group of commandoes took over Westgate Mall, killing 67.