“The people who collect tactical intelligence on the ground, day-to-day – and this isn’t Washington – but people collecting this stuff say they’re here, ISIS is here, they’re capable of striking,” said CNN national security analyst and former CIA operative Bob Baer.

“They don’t know what their plans and intentions are. But it’s a definite concern,” said Baer.

U.S. intelligence agents are keeping an eye on suspected ISIS militants who they believe have come across the Mexican border, or are American citizens that have come back from Syria, says Baer.