Russia has seized two North Korean fishing boats and 80 crew it says were illegally fishing in Russian waters
The North Korean crew on one of the boats, when they were caught, reportedly attacked Russian agents and injured three of them.
The boats and crew were taken to Russia's Nakhodka Port.
Moscow's foreign ministry summoned the North Korean ambassador and expressed grave concerns.
North Korean fishing boats have been seized many times by Russia for illegal fishing, and North Korea has also seized Russian boats.