Japanese Police have warned swimmers and beachgoers in Fukui to keep out of the water after reports emerged of wild dolphins attacking more than 10 people in the region, reported asahi.com
Signs have reportedly been erected at Fukui's beach, reading never touch dolphins.
The latest attack was reported on 24 July, when a man in his forties was bitten on his hand, according to Japanese media. The first incident of a marine mammal attacking a human was registered on 9 July.
According to English-language daily newspaper, The Japan Times, officials believe that "one rough dolphin" is behind the attack.
Masaki Tasui of Fukui's tourist ministry has stated that municipal authorities believe one dolphin was behind all the attacks, with the first one registered in April at the Koshino coastline.
Authorities at Koshino beach have also installed machines that emit ultrasonic frequencies under water to keep the mammals away from the beach.
Fukui Prefectural police said in a tweet on Monday: "Dolphins are considered very adorable, but if you approach wild dolphins carelessly, you might get bitten and injured."