(NewsNation) — Back-to-back shark attacks in the Florida Panhandle left one woman and two teens injured Friday.

The first attack happened when a 45-year-old woman was swimming with her husband around 1 p.m. Just an hour and a half later, two teens were attacked just four miles to the east.

Within 90 minutes, three attacks had been reported in south Walton County, prompting officials to warn beachgoers to stay on high alert.

The attacks are a phenomenon that Dr. Catherine Macdonald, the director of the Shark Research and Conservation program at the University of Miami, called “incredibly rare.”

“The footage that I’ve seen from that day suggests that there were a lot of fish present in the waters near the beach at the time,” Macdonald said. “And so anywhere that fish are, sharks might be actively feeding.”

Macdonald said that an increased number of fish near the coastline might warrant some heightened awareness among swimmers and surfers.

Macdonald also recommends staying near other people in the water, wearing bright colors and being aware of your surroundings when in open water.

“It’s very clear to me that the thing that sharks want the most is to get away from us and avoid us to the extent that they can,” Macdonald said. “So, making it very obvious that you’re a person is going to make it obvious to a shark that they don’t want anything to do with you.”

It’s not yet known what kind of shark or sharks bit the victims.