Authorities in Texas believe a single shark is responsible for several attacks that left two people hospitalized, one with severe injuries. The incidents occurred over the weekend off the coast of Galveston.

The first attack happened early Saturday morning when Tabatha Sullivent was bitten on the leg. She was rushed to the hospital with significant but non-life-threatening injuries. Later that day, another swimmer was attacked in the same area and hospitalized with less severe injuries.

Local authorities, working with marine biologists, believe the same shark is responsible for both attacks. Alarmingly, the shark was spotted near the beach shortly after the incidents. Increased beach patrols and drone surveillance have been deployed, and signs warn swimmers to stay out of the water.

“We urge everyone to stay out of the water until we can ensure it is safe,” said a spokesperson for the Texas Parks and Wildlife Department. The investigation is ongoing as authorities work to capture or deter the shark.