Six Chinese bombers flew through the strait between Japan's Miyako and Okinawa islands on Thursday, according to Japan's Ministry of Defense. However, the Chinese planes did not violate Japan's airspace, it added.
The Chinese military planes were conducting a routine exercise and passed through the strait legally, said Ren Guoqiang, a spokesman for China's Defense Ministry.
The Chinese military will organize similar exercises far out at sea according to the regional situation and mission needs in the future, he added. such activities should cause neither alarm nor too much speculation, and relevant parties should "get used to it," said Ren.
Japan's constant hyping of Chinese military activities is to fan the so-called Chinese threat and pave the way to amend its Constitution to legitimize its self-defense forces, experts said.
Miyako Strait is a strategic entryway into the western Pacific that has been regularly used by the Chinese military for drills far out at sea.
In April, Chinese naval ships passed through the strait for such a regular drill. In early March, Japan scrambled fighter jets after a total of 13 Chinese naval aircraft were spotted flying through the strait.
China's Air Force first flew over the strait in May 2015, but naval fleets have been transiting through the strait since 2009.
Lyu Yaodong, a researcher of Japanese foreign policy at the Chinese Academy of Social Sciences, said Japan often prided itself as the powerhouse in Asia in the 20th century, but this status has been challenged by China's rise.
"As a result, Japan will try everything to contain China's geopolitical influence, from the East China Sea to the South China Sea," he said. "Japan paints China's growing military strength as a looming threat so that its government can amend the constitution and legitimize its self-defense forces."
Major General Zhu Chenghu, a professor at the People's Liberation Army National Defense University, said Japan and the United States often use the so-called Chinese threat to justify their military presence in the region.
"The Miyako Strait is an international waterway and any military can pass through it legally," he said. "It is unfair to scrutinize the Chinese military for its passage. The Chinese military should pass it more often, so it will become normal and nobody will fuss over it anymore."