Donald Trump has said refugees entering America will stage 9/11-style attacks, and claimed their phone bills were being paid by the ISIS terrorist group.

The Republican presidential hopeful made the comments in an interview with the National Border Patrol Council’s “Green Line” radio show.

During the interview, Trump was asked whether he felt it would take another terrorist atrocity of the scale of the September 11 2001 attacks to make the American people “wake up about border security.”

Trump responded that he did, and then added ominously: “Bad things will happen – a lot of bad things will happen.”

“There will be attacks that you wouldn’t believe,” he added. “There will be attacks by the people that are right now that are coming into our country, because, I have no doubt in my mind.”

Noting that some of the refugees owned cellphones, Trump insisted the only way they could possibly afford them was if they were being sponsored by ISIS to carry out attacks.

“I mean you look at it, they have cell phones. So they don’t have money, they don’t have anything. They have cell phones.

“Who pays their monthly charges, right? They have cell phones with the flags, the ISIS flags on them. And then we’re supposed to say, ‘isn’t this wonderful that we’re taking them in?’ We’re led by people that are either incompetent or they don’t have the best interest of our country at heart.”

Trump’s latest controversial comments come after he backtracked on his pledge, made earlier in the Republican presidential campaign, to enact a total ban on Muslim immigration into the United States, claiming his initial comments were “just a suggestion.”