TOKYO, July 11 (AP/UNB) - Japan has summoned the Chinese ambassador in Tokyo to protest the alleged violation of its waters near disputed islands at the center of a heated territorial dispute.
 
Japan's top government spokesman says the Japanese coast guard on Wednesday spotted three Chinese patrol boats in Japanese territorial waters off one of the islands.

The Chinese vessels later left following warnings by the coast guard and are currently toiling just outside the territorial waters.  
 
Japanese officials reiterated their country's sovereignty over the islands, called Senkaku in Japanese and Diaoyu in Chinese. 

Surrounded by rich fishing grounds, the uninhabited islands are a flashpoint in diplomatic relations between Japan, China and Taiwan - all claiming them.
 
Chinese Foreign Ministry spokesman Liu Weimin said Wednesday that China has owned the islands since ancient times.