Japan says it has spotted an armed Chinese coast guard vessel for the first time in waters near islands that both countries claim.

The Japanese coast guard released a photo of the ship sailing in the East China Sea on Tuesday.

Chinese ships regularly sail around the disputed islands, known as the Senkaku in Japanese and the Diaoyu in Chinese. A Japanese coast guard spokesman said it was the first time an armed Chinese coast guard vessel had been sighted in the area.

The ship was one of four Chinese coast guard vessels spotted in the waters Tuesday, but was the only one that was armed. They did not come close enough to the islands to violate what Japan considers its territorial waters.