Four Chinese maritime surveillance ships were spotted in territorial waters around disputed Tokyo-controlled islands on Sunday, Japan’s coast guard said.
The ships were earlier sailing in the contiguous zone near the island chain but entered Japan’s 12-nautical-mile territorial waters around the East China Sea islands at around 1 p.m., the coast guard said.
This was a different Chinese fleet from that which spent several hours on Thursday in territorial waters around the islands, claimed by both Tokyo and Beijing, and provoked a strong protest from Japan, it added.
The so-called contiguous zone is an area that extends a further 12 nautical miles beyond the 12 nautical miles of territorial waters.
Tensions have risen in recent months over the islands, known as Senkaku in Japan and Diaoyu in China, which lie in rich fishing grounds. The seabed in the area is also believed to harbor mineral reserves.
Tokyo and Beijing are reportedly preparing for talks on the row which has hit multi-billion dollar trade ties between Asia’s two largest economies.