Russia on Friday said it detained more than 260 North Korean fishermen off its Far Eastern coast for poaching.
The mass arrests came after Russia detained more than 160 North Korean fishermen in the Sea of Japan last week.
The FSB security service said that it stopped "three schooners and five motorboats with 262 North Koreans onboard", Russian news agencies reported.
The fishermen did not resist arrest and were brought to the Far Eastern port of Nakhodka, it said.
Around 30,000 squid were seized along with illegal fishing equipment from the North Koreans, the security service added.
Last week, the FSB said three Russian coastguards were injured in a clash with a North Korean fishing boat, which it accused of carrying out an "armed attack."