The infringements were the first by Russia in five years, according to the Japanese defense ministry. A fighter fired a warning flare in response.

Russia and Japan have a territorial dispute over Russian-held islands near Hokkaido that were seized from Japan in the final days of World War II. Russian aircraft occasionally enter Japanese airspace, prompting Japan to scramble fighter jets in response.

Japan said a Russian surveillance plane violated its airspace three times on Monday.The Japanese Air Self-Defense Force scrambled fighters and fired flares in response.A Chinese military plane violated Japan's airspace last month.