Japan says Russia has seized three of its fishing boats near disputed islands off Northern Japan.
The Japanese Foreign Ministry says it is asking the Russian government for details regarding its three fishing boats, which were seized this week, and taken to Russian ports.
The Japanese Fisheries Agency says the three vessels are from cooperatives on Japan's main northernmost island of Hokkaido.
An agency official says the boats were catching Alaska cod within Russia's 320-kilometer exclusive economic zone (under a bilateral accord). The agency says Russia claims that one of the boats had taken in more fish than permitted, while the two others were found illegally within Russia's 20-kilometer territorial waters.
Japan's Foreign Ministry says a total of 28 crew members are being held in Russia.
The Russians have detained Japanese trawlers in its waters from time to time, but this is the first such reported incident of the year.
The two countries have had repeated disagreements over fishing rights in these waters, which are off disputed islands that both Japan and Russia claim. The islands, which the Russians call the Kurils and Japan refers to as its northern territories, were seized by the Soviet army in the closing days of World War II. The issue has prevented Moscow and Tokyo from signing a formal peace treaty for more than 50 years.
Earlier this year, Russia granted fishermen from Taiwan, Ukraine and both Koreas rights to fish in the disputed waters. Japan protested, but Russia brushed off the complaint, saying it has the exclusive authority to decide who can fish in those waters.