TOKYO -- Japan protested at Beijing after seeing Russian and Chinese warships outside its territorial waters surrounding the East China Sea islands.
Japan's Defense Ministry stated that a Chinese frigate was seen sailing within the "contiguous area," which is just outside Japanese territorial waters surrounding Senkaku Islands. This zone is also claimed by Beijing, who calls it the Diaoyu.
According to the ministry, the presence of the Chinese warship was confirmed approximately 40 minutes after a Russian ship had been in the water for over an hour.
It was unclear what caused the recent Chinese-Russian military activities in the region. Japanese defense officials suggested that the ships might have been there in order to avoid a Typhoon.
Seiji Kihara, Deputy Chief Cabinet Secretary, stated that Japan had lodged a protest to express "grave concern", and Beijing was informed.
"The Senkaku islands form an integral part of Japan's territorial history and international law. Kihara stated that the government would handle the matter calmly, but firmly in order to protect Japan's land, territorial waters, and airspace.
He said that there was no violation of territorial waters.
Beijing justified the entry of the frigate and criticised Tokyo's protest. Zhao Lijian, spokesperson for the Chinese Foreign Ministry, stated that the islands were Chinese territory.
At a regular news conference, he stated that "the activities of Chinese vessels within waters near are legal and justified." Japan cannot make such reckless remarks.
Japan regards China's assertive military activities in the East and South China Seas as a threat for regional stability. Toyo is particularly sensitive to Chinese activities around the disputed islands.
Kihara stated that Monday's incursion by the Chinese warship into the contiguous area, which is located between the territorial sea, and the wider exclusive economy zone, was the fourth such incident since June 2016.
This report was contributed by Ken Moritsugu, an Associated Press reporter from Beijing.