A foreign submarine was detected as it passed near Kagoshima Prefecture’s Amami-Oshima Island while submerged, the Defense Ministry said Saturday (June 20).
The ministry did not specify to which nation the submarine belongs but did confirm it traveled westward through the contiguous zone around the island on Thursday afternoon.
The submarine did not violate Japanese territorial waters around the island, it said.
The submarine was located in waters west of Yokoate Island as of Saturday morning.
In January 2018, Tokyo announced it had detected a Chinese nuclear-powered attack submarine in waters near the Japanese-controlled Senkaku Islands in the East China Sea. The islands are also claimed by Beijing, which refers to them as the Diaoyu.
The incident — the first time a Chinese submarine had been observed in the so-called contiguous zone around the uninhabited islets — triggered alarm in Tokyo, which complained to Beijing. The contiguous zone is a band of water beyond the 12 nautical mile territorial waters surrounding any national territory, it extends out to 24 nautical miles.