Rep. Mike McCaul: ISIS Called for US Attacks Last Week; No Credible Threat

House Intelligence Committee Chairman Mike McCaul said Tuesday that the Islamic State called for Paris-style terrorist attacks in the United States last week but that no specific threat existed.

"That's one of the greatest fears" in light of Tuesday's deadly assaults in Brussels, the Texas Republican told Wolf Blitzer on CNN. "When I talked to the FBI, they said there's no specific, credible threat in the United States.

"We are ramping up security in the United States, but also looking at visa applicants, visa waiver applicants — and looking at travel manifests on the airplanes trying to come into the United States," McCaul said.

But U.S. efforts are being slowed by encrypted technology and ISIS communications within "dark spaces" that cannot be accessed by law enforcement, he added.

"Factor in the idea that they can communicate now in what's called dark space and encrypted space," McCaul told Blitzer. "As the Paris-style attacks occurred, they had encrypted apps and we couldn't see what they were saying. That's why we couldn't stop it from happening.

"When I talked to federal law enforcement, that's our greatest concern here in the homeland. They could be here.

"We know there are terrorists communicating with individuals in the United States," he added. "We just can't see what they're saying."

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