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Police on the roof of a research building at Florida Atlantic University in Boca Raton, Fla., on Friday, Feb. 8.

Updated at 12:56 p.m. ET: Police shot and wounded a man Friday morning on the roof of a building at Florida Atlantic University in Boca Raton, Fla.

The victim, described as in his 20s, was in serious condition at Delray Medical Center, Boca Raton Police Chief Dan Alexander told reporters Friday afternoon. He said the man produced a knife when officers showed up to investigate a report that a homeless person was on the roof, "and shots were fired."

The shooting occurred on the roof of a building in Research Park, an enclave on the north end of the university's property. It isn't part of the main university grounds, and there was never a threat to students, faculty or staff, police told NBC News.

The campus wasn't evacuated or placed on lockdown, but people who work in the building where the shooting took place told NBC station WPTV of West Palm Beach that they weren't being allowed back in.

Michelle Acevedo and M. Alex Johnson of NBC News contributed to this report.

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