OREANDA-NEWS Beachgoers in Japan are being urged to stay away from dolphins following a spate of attacks thought to involve a single animal that have left at least six people with minor injuries.

The cetacean – believed to be an adult Indo-Pacific bottlenose dolphin – has bitten several swimmers at three beaches in Fukui prefecture on the Sea of Japan coast since the end of July.

Most of the incidents occurred within 10 metres of the shore, the Mainichi Shimbun said – a sign that dolphins in the area have grown accustomed to encountering humans in shallow water.

The newspaper said officials had installed an underwater device that emits ultrasonic waves in an attempt to deter the animals, but added that two attacks had occurred after the equipment was put in place.

In the most serious case, one swimmer required 14 stitches after being bitten on the hand on Koshino beach, a popular destination for sun-seekers.

In response, local police have started patrolling the beaches and handing out leaflets alerting people to the potential threat and warning them to keep their distance until the beach closes to bathers at the end of the month.

While dolphin attacks are extremely rare, they are not unheard of, especially if the animals feel threatened.

“There are certain body parts where dolphins don’t like to be touched, like the tip of their nose and their dorsal fin,” Masaki Yasui, an official from the tourism promotion department, told Agence France-Presse, adding that videos posted on social media appeared to show swimmers trying to touch the Fukui dolphin.

“We encourage visitors to watch the dolphin from afar if they come across it.”

Experts at an aquarium in Fukui said descriptions of the assailant’s appearance led them to believe that the attacks were the work of a single dolphin that was first spotted in the area in April.

The victims include two men in their 40s – both of whom received hospital treatment for minor injuries sustained on the same day at Koshino beach – and a man in his 60s who was swimming less than four metres from the shore at Takasu beach when he was bitten on his right arm.

“I’d heard about the dolphin on the news and was going to get out of the water immediately if I saw it, but by the time I noticed it, it was right next me,” he told the Mainichi.

The man said he had tried to prise the dolphin’s mouth open, but it refused to let go of his arm and appeared to be trying to force itself on top of him, nearly pushing him beneath the water. “I panicked, but I was saved when someone nearby drove it away,” he said.

One local caf? owner said dolphins had occasionally nudged swimmers in the past, but the recent incidents had escalated “to the point that they’re lunging on top of them”.