Independence Day celebrations on South Padre Island, Texas, turned bloody on Thursday when a shark targeted several people.

Game Warden Captain Chris Dowdy said it is believed that one shark measuring about six feet long was involved in the incidents, the Associated Press (AP) reported on Friday.

First responders initially treated one man at the beach after he was serenely bitten, the outlet continued.

“The Texas Parks & Wildlife Department said later in a statement that two people were bitten and two more ‘encountered’ the shark but were not seriously hurt. One of the bite victims was taken to a hospital in Brownsville, and the other was ‘flown out for further treatment,'” the AP article said.

Aerial video footage from the Department of Public Safety shows one of the sharks:

Witness Kyle Jud told reporters he watched as other beachgoers dragged a woman out of the water who appeared to have been bitten on her leg, NBC News reported Thursday.

“Beach patrol lifted her up — her calf was just gone, shredded. Horrific,” Jud recalled.

Video footage appears to show the moment the woman was pulled onto the beach as people worked to help and others screamed. As the camera nears the group tending to the woman, the water seems to be tinted red. The camera then pans out to the water and captures what looks like shark fins moving along in the waves.

When the camera pans back to the injured woman, her calf appears to be severely injured:

 WARNING – GRAPHIC VIDEO:

According to the Texas Parks & Wildlife Department, such shark encounters are not common in the state, the NBC report said. However, officials did note, “When bites from sharks do occur, they are usually a case of mistaken identity by sharks looking for food.”

One man who was swimming at South Padre Island said his son-in-law was pulled underwater and bitten by a shark, KVUE reported Thursday.

“I turned around, he wasn’t there anymore. I started swimming towards him and he jumped up out of the water saying, ‘Shark! Shark! Shark!’ and that’s when adrenaline kicked in and I went right after him,” he said, noting he carried him to shore and others ran over to help:

It has not yet been determined what type of shark was involved, but officials are investigating the incidents. For now, lifeguards are encouraging people to avoid the water or at least only go into it knee deep.