The Russian navy Vishnya-class intelligence-gathering vessel, number 535, is seen in this undated photo from the Japanese military. (Japan's Joint Staff)

A Russian intelligence-gathering ship spent more than a week in waters near Japan’s southern islands, including Okinawa and Kyushu, the country’s military announced Monday.

The Vishnya-class vessel, number 535, was first spotted at 10 a.m. on Feb. 1, sailing south approximately 30 miles southeast of Okinawa’s main island, Japan’s Joint Staff said in a news release.

The ship traveled east to west from Feb. 1-2, entering the contiguous zone southeast of Okinawa before moving northeast into the contiguous zone southeast of Kikaijima, an island in Kagoshima prefecture, on Feb. 4, according to the release.

A contiguous zone is a 12-mile-wide band beyond a nation’s 12-mile territorial limit, where limited enforcement rights apply under international law.

Between Friday and Saturday, the vessel was spotted sailing east to west in waters east of Miyazaki prefecture on Kyushu, including the contiguous zone. By Sunday, it was moving west through the Osumi Strait toward the East China Sea, the release said.

The same vessel previously sailed southwest through the Tsushima Strait on Nov. 11-12 before passing between Miyako Island and Okinawa’s main island on Nov. 14, according to the Joint Staff.

Japan’s Ministry of Defense and Maritime Self-Defense Force deployed ships and aircraft to monitor the vessel, the release said.

Russian military activity near Japan has increased in recent months.

On Nov. 11, a Yasen-class nuclear-powered submarine passed through the Soya Strait, which separates Japan’s northernmost main island, Hokkaido, and Russia’s Sakhalin Island. The submarine, accompanied by a flotilla of Russian vessels, was the most advanced of its kind to be spotted near Japan, according to the Joint Staff.

Russian aircraft have also entered Japanese airspace or flown near its territory multiple times in recent months.

On Sept. 23, an IL-38 reconnaissance plane entered Japanese airspace three times, prompting Tokyo to scramble fighter jets, which fired flares to warn off the aircraft.

On Sept. 12, two Russian Tu-142 patrol planes circled Japan’s four main islands for the first time in five years.

On Sept. 1, two Russian navy corvettes were seen 19 miles north of Cape Soya, heading west.