Thirteen Philadelphia Police officers have been removed from street duty amid questions about their roles in gun arrests, officials said Monday.

The department declined to identify the officers, the cases, or detail the nature of the internal review, other than to say it involved “discrepancies” flagged after an audit this year of about 325 arrests in gun cases. Sgt. Eric Gripp, a department spokesperson, said its Internal Affairs bureau launched the audit in March to evaluate the quality of cases.

District Attorney Larry Krasner said he believed that in some of the arrests under review, video from an officer’s body-worn camera appeared to conflict with the account they reported in police paperwork.

It was not immediately clear if any of the officers would be disciplined — Gripp acknowledged only that some cases require “further investigation.” And Krasner declined to say if his office expected to file criminal charges against any of them.

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But the decision to simultaneously pull multiple officers from the street is a relatively rarity for the department, which employs about 6,000 officers. Two years ago, 72 officers were placed on desk duty following a scandal over racist or offensive Facebook posts — the largest such action in modern memory. The majority ultimately kept their jobs.

Gun arrests have been a relative point of pride for the department during an otherwise-dismal year for violence across the city; commanders have frequently highlighted the record pace of such arrests as proof of their commitment to fighting crime. Philadelphia Police have arrested more than 1,900 people for illegal gun possession this year, according to a website maintained by the District Attorney’s Office — by far the highest year-to-date total since at least 2015.

Gripp, the police spokesperson, would not say how many total cases were flagged. And he declined to say if any of the 13 officers who were benched were associated with more than one problematic case.

He also declined to discuss possible discipline because he said the investigation remains ongoing. He said it was possible that Internal Affairs could refer some cases to the District Attorney’s Office for potential prosecution.

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John McNesby, president of Fraternal Order of Police Lodge 5, the officers’ union, said the department had not told the union what the discrepancies were or how the investigation might play out. He believed the officers who’d been benched were demoralized and felt as if their dangerous street work was being unfairly second-guessed by people sitting behind a desk.

“They’re not too happy, and hopefully these things can work themselves out in a quick manner,” McNesby said.

Anthony Erace, executive director of the Police Advisory Commission, a watchdog group, said the agency earlier this year forwarded some complaints it had received from civilians who claimed police had inappropriately seized their firearms. Erace didn’t know if those complaints were among the cases that Internal Affairs reviewed.

“We didn’t get an overwhelming number, but it was enough to notice that it might be an issue,” he said. “I’m glad the police department did this proactive work. It’s a good sign.”

Krasner also applauded Commissioner Danielle Outlaw for initiating the audit, saying it shows “that she cares about integrity.” And he said the use of tools such as body-worn cameras — instead of relying largely on someone’s testimony — could help the system become more fair and accurate.

“Body-worn cameras are going to prove to be one of the more important checks on the criminal justice system and what happens in a courtroom,” he said.

Staff writer David Gambacorta contributed to this article.