The Chinese People Liberation Army Navy (PLAN) ships were spotted circling around Japan for days from June 12, involving two Chinese guided-missile destroyers and one supply ship, Japan’s Defense Ministry said on June 30.
The ministry said in a statement (pdf) that Japan’s Maritime Self-Defense Force (JMSDF) detected three Chinese navy ships sailing 130 kilometers (80 miles) northeast of Miyako Island and entering the disputed East China Sea on June 29.
The PLAN’s two guided-missile destroyers, identified as the Renhai-class and Luyan III guided-missile destroyers, were first spotted sailing through Japan’s Tsushima Strait from June 12 to June 13.
The JMSDF detected one PLAN’s border-class supply ship sailed east in the Tsugaru Strait on June 16, while the two destroyers sailed east in the Soya Strait from June 16 to June 17.
The ships were sighted sailing together 220 kilometers (136 miles) southeast of Inuzaki island on June 20, and between Sumiju and Torishima Islands—which is part of the Izu Islands group—on June 21.
Following that, the JMSDF deployed two destroyers and a patrol helicopter on June 30 for a joint exercise with the Japan Coast Guard’s patrol vessels and helicopter in the east of Izu Oshima, which is part of the Izu Islands.
“Through this exercise, we improved the skills of the JMSDF and strengthened our joint response capability with the Japan Coast Guard,” the JMSDF commander said in a statement.
China has built up its military presence in the South China Sea and made numerous incursions into the East China Sea, where the Senkaku Islands are located.
Japan has mostly controlled the Senkaku Islands since 1895, but Beijing began asserting its right over the islands in the 1970s and called them the Diaoyu Islands.
Two Chinese Coast Guard ships entered the area off the Senkaku Islands on June 18 and shadowed a Japanese fishing boat sailing in the area. The Chinese vessels departed from the area at about 11:25 a.m. local time on June 19.
Japan also lodged a protest against Beijing’s “unilateral development activities” in the East China Sea on June 17, after its navy detected that China was laying the groundwork for a new structure in the disputed waters.