A Japanese fishing boat collided with a South Korean one in the Sea of Japan on Thursday morning, with all 13 personnel aboard the latter rescued and all 21 aboard both vessels unhurt, the Japan Coast Guard said.

The collision occurred at around 9:35 a.m. about 230 kilometers northwest of the Noto Peninsula near fertile fishing grounds.

The 164-ton Japanese squid fishing boat from Yamagata Prefecture, northeastern Japan, had eight people -- four Japanese and four Indonesian trainees -- aboard, while the 48-ton South Korean boat, which was inundated with water, had South Korean and Vietnamese crew members, according to the coast guard.

[Getty/Kyodo]

The coast guards of the two countries are looking into the cause of the collision.

Japanese Chief Cabinet Secretary Yoshihide Suga told a news conference in Tokyo he had been informed that the Japanese boat sustained minor damage and a Japan Coast Guard patrol vessel had arrived to provide assistance.

The accident occurred around waters called Yamatotai in Japan's exclusive economic zone. The waters are known as fertile fishing grounds for squid and other types of fish.