Tokyo, Japan (CNN) -- The Japanese government lodged a protest with the Chinese government Monday about the alleged presence of Chinese patrol boats near disputed territory, according to Japanese media.
Japanese naval authorities spotted two Chinese patrol boats late Sunday near islands that have been at the center of recent diplomatic tensions, Japan's Kyodo News Agency reported Monday.
Both countries claim sovereign rights to the islands called the Senkaku Islands in Japanese and the Diaoyu Islands in Chinese.
The boats were in Japan's "contiguous zone" but did not cross into Japanese territorial waters, Kyodo reported, sourcing Japan's coast guard.
But Japan's Chief Cabinet Secretary Yoshito Sengoku said in the protest message to China that seeing Chinese patrol boats made his government feel "uncomfortable," according to Kyodo.
China's foreign ministry has claimed that its boats' patrols are both legal and based on need.
Japan's Chief Cabinet Secretary Yoshito Sengoku said Monday that Japan will step up its monitoring activities around the Islands, according to Kyodo.
Japan will add six submarines to its current fleet of 16 during the next four years as it sees increased naval activity from Asian neighbor China, according to news reports from Tokyo last week.
CNN
