9th joint strategic aerial patrol conducted over Sea of Japan, also known as East Sea, says China's Defense Ministry
The Chinese and Russian militaries on Friday conducted a joint aerial patrol over the Sea of Japan, also referred to as the East Sea.
China's Defense Ministry said in a statement that this was the ninth joint strategic aerial patrol by the two militaries to take place.
It added that the joint patrols were held as part of bilateral military cooperation.
However, South Korea's military has said that five Chinese and six Russian military aircraft entered the country's air defense identification zone "without prior notice" on Friday afternoon, local time.
"There was no violation of South Korean sovereign airspace," the South Korean Joint Chiefs of Staff said, adding that its military "implemented tactical measures by deploying Air Force fighter jets in preparation for an emergency."
The Chinese and Russian militaries held similar patrols in July when they conducted joint air patrols over the Bering Sea.
It was the first time that two Russian Tu-95 and two Chinese H-6 bombers were spotted off the coast of the US state of Alaska where they were intercepted by American and Canadian fighter jets.
Last month, Russian and Chinese border guards held their first joint patrol in the northern Pacific Ocean.
The naval group consisted of the Russian patrol ships Petropavlovsk-Kamchatsky and Anadyr, along with the Chinese coast guard vessels Meishan and Xiushan.
They traversed the Sea of Japan before making their way northeast into the Bering Sea, passing through the Bering Strait into the Chukchi Sea.