Police intercepted suspicious coded radio messages to and from a North Korean ship near the Noto Peninsula in 1977, shortly before security guard Yutaka Kume was apparently abducted nearby, sources said Friday.
The radio messages prompted Ishikawa Prefectural Police to set up security checkpoints at railway stations and on roads and ask local hotels and inns to report any suspicious activity, the sources said.
As a result, a woman managing an inn in Noto reported to police twice that two guests -- Kume and a Korean man -- were acting strangely, including eating meals without saying a word to each other and going out at midnight.