Donald Trump charged that there were “many, many people” in the United States who are “sick with hate” and willing to carry out terrorist attacks like the mass shooting this weekend at a gay club in Orlando, Florida.

Trump, who was quick to label the shooting an act of “radical Islamic terrorism,” said in a Monday appearance on “Fox and Friends” that American Muslims know who these individuals are.

“We have to be extremely strong,” the presumptive GOP nominee said. “We have to be very strong in terms of looking at the mosques. You know, which a lot of people say oh, we don’t want to do that, we’re beyond that. Brian, that man yesterday was sick with hate. There are many, many people, thousands of people already in our country that are sick with hate. And people that are around him, Muslims know who they are, largely. They know who they are. They have to turn them in. They know who they are. They see them.”

Trump first alleged that Muslim Americans knew about but failed to report potential terrorists after the mass shooting in San Bernardino, California last December. That incident also prompted Trump to propose a “total ban” on Muslim immigration, which he has renewed in the wake of the Orlando shooting.

“We’re allowing people to come into our country that are no different than this maniac,” Trump said of shooter Omar Mateen.

Trump criticized President Barack Obama and his Democratic rival Hillary Clinton as “inept” in their response to terrorist attacks, saying they want to admit refugees even though we “have no ideas who they are.”

“We have no idea as to paperwork, as to where they came from,” Trump said, despite the extensive years-long screening process refugees must go through. “This could be the all-time great Trojan horse. This could be the legend of the Trojan horse. This could be it. I used to say it with a smile, maybe is it possible at the very early stages, and the more you’re thinking, a thing like that could never happen. I’m starting to think it could happen.”

Asked to defend his tweets saying he didn’t want “congrats” for being “right on radical Islamic terrorism,” Trump repeated the sentiment.

“I’m getting thousands of letters and tweets that I was right about the whole situation,” Trump said. “I mean, I’ve been right about a lot of things, frankly, I was right about take the oil, I was right about many, many things.”

“I don’t want congratulations, what I want them to do is be tough and vigilant,” he added.

Trump, who will give speech on his anti-terror proposals Monday, also said the US should launch a military response overseas in response to the Orlando attack.

“We have to really increase the bombing,” he said.