The Japan Coast Guard is planning to build bases for seven new large patrol ships in a bid to improve response time to incidents — including the frequent intrusions by Chinese vessels into Japanese waters around the Senkaku Islands in the East China Sea, according to a source.

The coast guard is looking at up to four sites — the city of Tsuruga in Fukui Prefecture, the city of Kagoshima, and Okinawa Prefecture's Ishigaki Island and Miyako Island, the source said. The plan is to start building the bases as early as fiscal 2019 — which starts in April next year — following consultations with local communities.

The Japan-controlled Senkaku Islands, which are also claimed by China, continue to be a source of friction between Tokyo and Beijing. Chinese coast guard vessels have frequently entered Japanese waters around the uninhabited islets as part of China's claim. The islands are called Diaoyu in China.