Dolphins began to attack people in the Japanese city of Fukui, NHK TV channel reports.
Just the day before, the animals had bitten two people on the beach, so it was closed.
The city administration has installed new buoys, trying to scare off ultrasonic dolphins. It also urges beach visitors not to try to touch the dolphins, or even ride them, it is best to watch them from the shore.
Dolphins have been arriving in Fukui since May. In July they began to attack people.
