The chairman of the House Committee on Homeland Security spoke Friday at MacDill Air Force Base in Tampa, saying investigators are calling the deadly shootings of four Marines in Chattanooga, Tennessee, a "terrorism incident."

Rep. Michael McCaul, R-Texas, said officials were working to find out if the gunman, 24-year-old Muhammad Youssef Abdulazeez, was motivated or influenced by the Islamic State group, also known as ISIS, which has been calling for "lone wolf" style attacks like Thursday's.

Rep. McCaul said the government needs to be ready for this new kind of terrorism.

"The threat is real, and it comes from the internet. This is a new generation of terrorists, this is not Bin Laden," said McCaul.

McCaul says the extremists are radicalizing people online using secret backchannels of the internet to communicate. Although the FBI is still investigating whether the shooter in Chattanooga had any ties to ISIS, McCaul says lawmakers need to shift priorities to keep America safe.

"We spend billions of dollars to stop the terrorists, trying to stop them overseas, stop them from coming in the country. But we do little to counter violent extremism in the United States," he said.

Abdulazeez was killed Thursday after investigators said he shot multiple rounds at a military recruiting center in Chattanooga, and then drove to a Navy-Marine training center seven miles away, killing four Marines and seriously injuring a sailor.