A Chinese survey ship was spotted within Japan's exclusive economic zone off Amami Oshima Island in Kagoshima Prefecture on Sunday, according to the Japan Coast Guard.
The JCG's 10th Regional Coast Guard Headquarters, based in the city of Kagoshima, said the same day that a patrol ship found the Chinese vessel releasing what appeared to be a wire into the sea about 380 kilometers west of the island around 6:15 a.m.
The patrol ship's crew urged the Chinese vessel by radio to stop its activity, saying that marine research without Japan's consent is not permitted.
Around 9:45 a.m., the Chinese ship crossed the geographical equidistance line between Japan and China to the west and left the EEZ, the regional headquarters said.
With your current subscription plan you can comment on stories. However, before writing your first comment, please create a display name in the Profile section of your subscriber account page.