Defense officials in Japan say Chinese and Russian naval vessels have jointly passed through the Tsugaru Strait located between Japan's main island of Honshu and Hokkaido.
It is the first time that Japan's defense ministry confirmed Chinese and Russian warships going through the strait simultaneously.
The defense ministry says that the aircraft and vessels from the Maritime Self-Defense Force spotted a total of 10 Chinese and Russian naval ships about 110 kilometers southwest of Hokkaido's Okushiri Island in the Sea of Japan at around 8 a.m. on Monday.
Five of the vessels were confirmed to belong to the Chinese navy, including a state-of-the-art Renhai-Class missile destroyer.
The other five were confirmed to be Russian warships, including a destroyer.
The ministry says that the fleet entered the Pacific Ocean through the Tsugaru Strait in the afternoon.
The Tsugaru Strait is an international waterway where foreign ships, including warships, are allowed to navigate.
An NHK helicopter crew observed the 10 ships in an apparent formation navigating eastward shortly after 2 p.m.
China and Russia had conducted joint military exercises in the Sea of Japan for four days through Sunday. The vessels spotted in the Tsugaru Strait are believed to have taken part in the drills.
The Japanese defense ministry is analyzing the purpose of the navigation.
Russia's defense ministry announced on Monday that the joint Russian-Chinese naval exercise had ended in the Sea of Japan.
The ministry said 15 warships including destroyers and submarines from the navies of the two countries took part in the exercise. It explained that personnel performed more than 20 combat drills, including communications, mine removal and artillery firing at floating targets.
The Russian ministry said the joint exercise had been held annually since 2012. But last year, it was cancelled due to the coronavirus pandemic.
It also said that a US naval ship attempted to enter Russia's territorial waters in the Sea of Japan and approached to within 60 meters of a Russian warship on Friday. The ministry said it had lodged a protest with the United States.
The US side called Russia's claim false and said the US naval ship's interaction was safe and professional.
