The Japan Coast Guard says more than 300 North Korean fishing boats have been spotted in Japan’s exclusive economic zone off the Noto Peninsula since late May.
In recent years, North Korean squid-fishing boats have illegally operated from early summer to winter in a fishing ground known as Yamatotai off the peninsula on the Sea of Japan.
The Coast Guard says the illegal boats began to appear late last month ahead of this year’s full-fledged fishing season.
Footage released by the Coast Guard shows the boats’ crews abandoning ropes apparently tied to fishing gear after being sprayed by water cannon.
The Coast Guard says it warned 318 boats to leave Japanese waters, and has used water cannon against 50 of them.
It is conducting patrols around the clock to step up its crackdown as the illegal fishing continues.