TOKYO - Four Chinese maritime surveillance ships were Sunday sailing in the contiguous zone near a disputed island chain in the East China Sea, Japan's coastguard said.
This was a different Chinese fleet from that which spent several hours in territorial waters around the Tokyo-controlled islands on Thursday 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 harbour 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.