Japan’s defense ministry said on Tuesday that four Chinese and Russian bombers flew together over waters near Japan, and air defense forces responded with fighter jets.

Although Japanese airspace was not violated, the ministry has expressed serious concern to China and Russia through diplomatic channels, viewing the move as a clear show of force.

Recently, China and Russia have become more active in joint military operations in an apparent attempt to challenge the international order led by the US and other Western countries.

Two Chinese H-6s joined two Russian Tu-95s over the Sea of ​​Japan and flew together into the East China Sea, the ministry said, adding that the bombers joined two Chinese fighter jets that were believed to be above the waters.

Meanwhile, the general staff of the South Korean military said that eight military aircraft – four each from China and Russia – intruded into the designated air defense reconnaissance zone of Seoul on the same day.

In response, South Korea raised fighter jets, as well as Chinese and Russian aircraft.bombers included, they did not enter South Korean airspace, the report said.

The zone serves as a national defense perimeter used to decide whether or not to push back fighters when foreign aircraft enter without prior notice.

On the same day, China and Russia also conducted joint air patrols over the Sea of ​​Japan and the East China Sea, according to the Chinese Defense Ministry.

The sixth joint patrol between the two countries comes amid increased military cooperation between Beijing and Moscow.

Chinese and Russian bombers also made joint flights over Japanese waters in November last year.

Source: Reuters, Kyodo.