Two people were bitten by a shark in the waters off South Padre Island in Texas on July 4th as the US marks its Independence Day.

“Details at this time indicate that two people were bitten and two people encountered the shark but were not seriously injured,” said the Texas Parks and Wildlife Department in a statement.

The two bite victims were taken to Valley Regional Medical Center in Brownsville. One is being treated there, while the other was flown out for further treatment.

A third person was hurt, but not seriously, while trying to help one of the bite victims. It is unclear exactly how they were injured. Another beachgoer said they felt a shark brush against them as it swam by.

“Shark encounters of this nature are not a common occurrence in Texas,” the department noted. “When bites from sharks do occur, they are usually a case of mistaken identity by sharks looking for food.”

Earlier, Texas Parks and Wildlife Department Game Warden Captain Chris Dowdy told CNN affiliate KRGV that at least four shark-related incidents had been reported at South Padre Island. The attacks were likely associated with the same shark, which later swam to open waters.

Two off-duty Border Patrol agents from the Search, Trauma, and Rescue Unit pulled one of the victims out of the water and applied a tourniquet to their leg, according to a US Customs and Border Protection official.

One of the attacks was reported to the South Padre Island Police Department at 11 a.m. Officers provided immediate treatment and transported the male victim to a local hospital, said Nikki Soto, the city’s Public Information Officer.

South Padre Island Beach patrol, fire, and police are patrolling the shoreline and using drones to watch for the shark.

Nereyda Bazaldua told CNN her daughter was one of those bitten. Bazaldua said her two teenage daughters were in shallow, knee-deep water near the shore playing on boogie boards when they began screaming, “Shark!” When her 18-year-old daughter Victoria came out of the water, Bazaldua said she “could see some blood coming down her leg.”

“The shark pushed into her, five to six of his teeth scratched her leg,” Bazaldua said. “The wounds aren’t deep.” She added that the shark lingered in the water for 20 to 30 minutes before moving along.

A Texas Department of Public Safety helicopter flew low over South Padre Island and used deterrence measures to keep the shark from getting close to shore after the encounters, said Lieutenant Chris Olivarez.

“The Texas Department of Public Safety’s Aircraft Division responded to South Padre Island to assist local authorities with a shark attack,” Olivarez said.

Patrick McNulty, mayor of South Padre Island, said: “Our hearts and prayers are with the injured and their families and we hope for a speedy recovery.”

According to the International Shark Attack File, run out of the University of Florida, there had been less than 10 shark bites reported in Texas since 2012. This places Texas behind Florida, which leads with 259 reported bites, followed by Hawaii (76), South Carolina (45), North Carolina (31), and California (29).