A Chinese missile destroyer conducted a live-fire drill inside Japan’s Exclusive Economic Zone (EEZ) near Okinotorishima island, the nation’s southernmost point, the Defense Ministry announced on July 21.

It marks the first time the ministry has publicly confirmed such a drill by Beijing within the EEZ.

The drill was held while a Russian frigate was also operating in the area, deepening concerns in Tokyo about growing military coordination between the two nations.

The ministry said Japan’s Maritime Self-Defense Force on July 19 spotted the Chinese warship as part of a four-vessel flotilla that included another Chinese destroyer, a replenishment ship, and the Russian frigate. They were about 330 kilometers southwest of Okinotorishima, a tiny Tokyo-administered atoll.

Later, one of the Chinese missile destroyers broke off to conduct the shooting drill about 180 km from the atoll, prompting the MSDF to conduct warning and surveillance activities.

Japan had been tracking the flotilla since July 16, when it was seen sailing southward between Okinawa’s main island and Miyakojima island into the Pacific Ocean.

“We recognize this as part of a move to strengthen coordination between the two militaries, and the MSDF is appropriately conducting warning, surveillance, and intelligence gathering,” Chief Cabinet Secretary Minoru Kihara said at a news conference on July 21.

“We will continue to watch the movements of Chinese and Russian vessels with concern, and will do our utmost to conduct warning and surveillance in the sea and airspaces surrounding our country,” he said.

The ministry’s announcement followed remarks a day earlier by Defense Minister Shinjiro Koizumi, who revealed the live-fire drills in a speech at the Farnborough International Airshow in southern England.

Koizumi also highlighted 10 previous joint flights by Chinese and Russian bombers near Japan, expressing alarm that “military cooperation between China and Russia is being strengthened.”