VLADIVOSTOK, September 19. /TASS/. Four Russian border guards, injured while detaining suspected North Korean poachers in the Sea of Japan earlier this week, have been flown by helicopter to medical facilities in Russia’s Far Eastern city of Vladivostok.

"The injured officers of the Border Guards Directorate of the Federal Security Service (FSB) department in the Primorsky region, who were injured while detaining poachers from DPRK in the Sea of Japan, have been flown by a helicopter to medical facilities in Vladivostok," a source in the Far Eastern transport investigation department of the Russian Investigative Committee told TASS on Thursday.

When asked about the condition of the officers, the source said only that two officers had been operated on.

A spokesperson for the regional FSB Border Guards Directorate said the condition of officers is not life-threatening.

"Their condition is satisfactory, the wounds pose no threat to their lives and health," he said.

The arrival of convoy with the detained North Korean fishermen, initially expected on Thursday, has been delayed until Friday or Saturday due to unfavorable weather conditions.

"They move very slowly and are still very far away. Besides, the weather at sea is now changeable and unfavorable. Don’t wait for them today. <...> They will arrive tomorrow, or maybe even the day after tomorrow, but everything depends on weather," the regional border guards department’s press service said.

A FSB spokesman reported on Tuesday that Russian border guards had spotted two North Korean vessels and 11 motorboats poaching in Russia’s exclusive economic zone near Yamato Bank in the Sea of Japan. The crew of one of the vessels staged an armed attack on inspectors of the Russian coastal patrol ship, injuring four of them. A total of 161 residents of North Korea were detained, some of them were injured.

The Russian Investigative Committee said a criminal case had been launched into the attack on Russian border guards.