A congressional Homeland Security Committee report released last week noted that Minnesota has the highest number of American recruits for the Islamic State.

The report said more than 250 Americans "have tried or succeeded in getting to Syria and Iraq to fight with militant groups."

Of the 58 cases that are public, 26 percent of the recruits were from Minnesota, according to CBS Minnesota.

The more than 250 identified were "individuals who were stopped before traveling, who made it to the conflict zone and are still there, who were killed, and others who have come back."

Following Minnesota in the list are California with 12 percent and New York/New Jersey with 12 percent.

The report said US recruits are "young and most are men." The average age in the sample is 24 years old, with the youngest at 15 and the oldest at 47.

It said young people from at least 19 US states have sought to become foreign fighters in Syria and Iraq.

The report said online propaganda and social media are major factors in US recruitment.

"In almost 80 percent of cases, we found examples of US foreign fighter aspirants downloading extremist propaganda, promoting it online, or engaging with other extremists on social media. Some communicated with ISIS fighters in Syria using secure messaging apps like Surespot or posed questions to overseas jihadists via the anonymous website Ask.fm; others promoted jihadist content across multiple platforms," it said.

US recruits are motivated to join terrorist groups due to the alleged inspiration they get from jihadist ideology and the opportunity to live in the caliphate. Others join because of adventure, camaraderie and sense of belonging, the report said.

"In almost all cases, though, suspects feel excluded from society or think they have failed to live up to expectations," it said.

The report said the US government lacks an effective strategy to prevent recruits from going to Syria while law enforcement agencies are increasingly failing to monitor possible recruitment by ISIS.

"Americans who make it to the conflict zone are reaching back to recruit others," the report said. "A number of the cases we reviewed involved Americans who made it to Syria and attempted to remotely recruit others back home."

It also highlighted the dangers of "returnees"—Western recruits who go back to their native countries after fighting abroad. It said dozen returnees returned to the US.

While there are an increasing number of recruits from the US, the largest came from Tunisia with 5,000 fighters; 1,550 from France and 700 from the UK.

There are about 25,000 foreign fighters who have joined ISIS, coming from more than 100 countries.