GOP presidential front runner Donald Trump blasted Mayor Bill de Blasio on Sunday, accusing him of shutting down NYPD's controversial unit tasked with surveillance of the local Muslim community.

"I want mosques surveiled. We were doing it New York City for a while until the worst mayor that New York City has ever had got elected — de Blasio, which was a fluke," Trump said on ABC's "This Week."

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Trump went on to say that "a very good source" told him authorities were getting "big material and good material."

"They were stopping problems and potential problems by learning what was happening," Trump said.

The statement comes days after NYPD Commissioner Bill Bratton repeatedly defended his decision to close the department's demographics unit in 2014.

"Is that an appropriate use of a dozen police detectives who are supposed to be helping in the fight against terrorism?" Bratton asked at a panel event Thursday. "That not a single piece of actionable intelligence came out of their multi-years of work."

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A spokeswoman for Trump did not immediately respond to a request for comment.

The real estate magnate turned political figure doubled down on his Twitter attack of de Blasio from Friday, in which he told the mayor to "focus on running #NYC & all of the problems that he has caused with his ineptitude, & not be so focused on me!"

Earlier in the day, de Blasio voiced support for his commissioner.

“Who are you going to trust on security and keeping people safe?" de Blasio said on WOR710 radio. "Bill Bratton or Donald Trump?"