Beware: The U.S. Open is a no-drone zone.

The New York Police Department warned Monday on the Grand Slam event’s opening day that it has a zero-tolerance policy toward drones buzzing the tournament, and any seen hovering over Flushing Meadows will be taken out immediately.

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Exactly how was not specified, with NYPD Deputy Commissioner of Intelligence and Counterterrorism Rebecca Weiner saying only that the department “will be deploying our counter-drone capabilities.” In the past, police have taken out problem drones by jamming their radio signals.

In 2015, a drone buzzed the court during a nighttime women’s match at Louis Armstrong Stadium and crashed into an empty section of seats. No one was injured.

Weiner warned that anyone caught flying drones this year risks possible arrest and having their equipment confiscated.

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The Associated Press contributed to this article.