'Thousands' of ISIS terrorists may already be in U.S. cities, waiting for attack signal, security experts' group warns

Heavily armed police officers secure the area at Union Station in Washington D.C., on Nov. 25, 2015.Reuters

"Thousands" of Islamic State (ISIS) terrorists could already be spread out in major U.S. cities, waiting for the signal to attack similar to what a few of them did in Paris, a group of national security experts warned.

The Threat Knowledge Group, a training and strategic threat analysis group with links to the Pentagon, has issued an alarming report stating that ISIS has already recruited thousands of supporters in the U.S.—far more than previously thought—through the Internet and social media, according to WND.com.

The report accuses President Barack Obama of not only "downplaying" the ISIS threat but also adding "more fuel to the fire" with his decision to take in thousands upon thousands of Muslim refugees.

"It is clear that the United States is a primary target for ISIS and that ISIS has the necessary supporters in place and the financial means to carry out such an attack. The challenges of screening incoming refugees may further exacerbate the problem," the report states.

"While accepting those who flee from persecution and violence is a valued component of the American tradition, we must acknowledge that ISIS and other terrorist groups may use the refugee track as a way to gain access to the United States with the purpose of carrying out an attack."

The group noted that the U.S, is already importing 70,000 refugees a year for many years now, more than half of them coming from Muslim-dominated countries with active jihadist movements such as Somalia and Iraq. It said Obama has promised to increase that number to 85,000 this year and 100,000 the following year.

Even discounting the entry of terrorists embedded in the batch of new refugees, the U.S. still faces a national security problem based on statements made by the Obama administration itself which revealed that "around 200" Americans had left the country to join ISIS, the report says. The group warned that some of those radicalised Americans could come back using their American passports and wreak havoc at home.

In a recent report, the FBI said it has about 900 active ISIS investigations in all 50 states.

The Threat Knowledge Group is headed by counter-terrorism expert Sebastian Gorka, a U.S. Department of Defense adviser. The group, composed of academics and policy advisers, has come up with a list of 82 persons in the U.S. who were affiliated with the ISIS and apprehended by law enforcement officials.

The report states that almost a third of these arrested individuals had plotted attacks against Americans on U.S. soil in the last 18 months.

"Based on the evidence available, the number of ISIS supporters in the United States measures in the thousands, rather than hundreds," Gorka said in the report, which he co-authored with his wife, Katharine Gorka.

At the end of the report, the Gorkas issued recommendations on how to counter the threat.

One of their recommendations is for U.S. authorities to "stop downplaying the seriousness of the threat so that individuals and law enforcement can be properly prepared."

They also urged the police to work with educators to identify the signs of radicalisation among students, focus more on tracking the ISIS religious propaganda online, and develop a more rigorous screening process for refugees from the Middle East.