With North Korea launching three missiles in May, including one early Monday morning that landed in Japan's exclusive economic zone, concern is intensifying among fishermen whose boats ply the waters in the Sea of Japan that they could find themselves in the path of an incoming projectile.

The government estimates that the most recent missile fired by North Korea landed about 500 km from Sado Island in Niigata Prefecture and nearly 300 km from the Oki Islands, which sit offshore of Shimane Prefecture.

Local governments along the coast from Akita to Shimane prefectures have recently stepped up measures to ensure fishing boats at local ports are safe and accounted for when they hear media reports of a North Korean missile launch.