Fishermen and local officials on the Sea of Japan coast rushed Monday to gather information and confirm the safety of fishing boats after North Korea fired missiles into Japan's exclusive economic zone 300 to 350 km west of Akita Prefecture.

The fishermen's union from the prefecture confirmed that no fishing boats had been operating in the immediate area after the Fisheries Agency issued an alert about the incident at around 9:30 a.m.

"Though no fishing boats based in our prefecture usually operate in those waters, we will continue to collect information," a union official said.

Hiroaki Fukuda, 59, an official of the fishermen's union in Aomori Prefecture, expressed concern, saying that union members operate in the Sea of Japan.

"We cannot fish without fear," Fukuda said.

Fishermen operate mainly along the coast during this season, but in May and subsequent months many will venture further out into the Sea of Japan to catch squid, according to a local union in Nakadomari, Aomori Prefecture.

"It is possible that a missile might come down during that season, and that scares me," a person related to the fishing industry said.

This comes after another incident in August last year when North Korea test-launched a ballistic missile into the sea 250 km west of the Oga Peninsula in Akita Prefecture.

"I'm concerned that the incident followed the one last year," said a crisis management official in the city of Oga.

Akita Prefecture's disaster prevention department said no damage from Monday's incident had been reported.

"We are waiting to receive information from the central government," said an official in Sakata, Yamagata Prefecture.