Washington ? The U.S. was slow to take seriously the threat posed by homegrown radicals and the government has failed to put systems in place to deal with the growing phenomenon, according to a new report compiled by the former heads of the Sept. 11 Commission.

The report says U.S. authorities failed to realize that Somali-American youths traveling from Minnesota to Mogadishu in 2008 to join extremists was not an isolated issue. Instead, the movement was one among several instances of a broader, more diverse threat that has surfaced across the country.

“Our long-held belief that homegrown terrorism couldn’t happen here has thus created a situation where we are today stumbling blindly through the legal, operational and organizational minefield of countering terrorist radicalization and recruitment occurring in the United States,” said the report.

As a result, there is still no federal agency specifically charged with identifying radicalization or working to prevent terrorist recruitment of U.S. citizens and residents, said the report, which was released Friday by the Washington-based Bipartisan Policy Center’s National Security Preparedness Group.

The group, headed by former 9/11 commission leaders Tom Kean and Lee Hamilton, laid out a detailed description of domestic terror incidents ranging from the Fort Hood, Texas, shooting spree and the attempted Christmas Day airliner attack in late 2009 to last May’s botched truck bombing in New York’s Times Square.

“The threat has both diversified and become much more complex than it has been at any time since the attack on Sept. 11, 2001,” said Bruce Hoffman, one of the authors of the report. “There is no single profile of the terrorists threatening the United States today. What we see is an adversary that in essence is drawn from all sectors of society and all walks of life.”

Over the past year, terrorism experts and government officials have warned of the threat posed by homegrown radicals, saying terror recruits who go abroad could return to the U.S. to carry out attacks.