It's the second major Russia-North Korea incident on the high seas in as many months: on Tuesday a clash between North Korean fishermen and Russian border patrol ships in the Sea of Japan ended in an exchange of fire and 161 North Koreans held captive.

The North Korean vessels, described as poachers given they were said to be fishing in Russian economic territory, were halted by Russian border patrol, after which one of the North Korean boats opened fire on the Russians, which wounded at least three border patrol guards.

Image source: TASS

In total Russian officials reported two schooners and 11 motorboats from North Korea were spotted violating Russia’s Exclusive Economic Zone. Following the nearly deadly exchange of fire the Russians detained all the vessels and a reported 161 crew members, some of them wounded. This after initial reports cited up to 80 North Koreans detained.

Russia promptly summoned the North Korean Charge d’Affaires to the Foreign Ministry over the incident, demanding an explanation of the egregious and blatant violation of its territorial waters.

Russia's Tass news agency cited a Federal Security Service (FSB) statement on Tuesday saying the "crew of a North Korean vessel [with over 45 people onboard] carried out an armed attack on the members of a monitoring group of the border guards' ship" in the Sea of Japan resulting in "three servicemen received various injuries," according to the report.

The Russian Pacific Fleet is based out of Peter the Great Bay, the largest in the Sea of Japan, and its port city of Vladivostok, home to Russia's major Far East region/Pacific naval base since the 18th century.

A prior incident occurred in late July, but involving the opposite scenario: at that time 15 Russian nationals along with two South Koreans were detained by the DPRK after their fishing vessel drifted into North Korean waters.

Though Moscow and Pyongyang currently enjoy positive trade and diplomatic relations, a 2016 incident also involving a North Korean vessel drifting into Russian waters did turn deadly and ranks as the most serious encounter of recent years.

That prior incident involved a packed North Korean commercial fishing vessel (reports at the time indicated 48 crew) allegedly "acting aggressively" and attempting to flee when boarded by Russian border patrol guards in the Sea of Japan. One Russian border patrol officer and nine North Korean fishermen were injured after the Russians opened fire as the crew resisted, with one North Korean later dying in the hospital.

No doubt Pyongyang has this prior incident front and center in its mind as it will likely seek to negotiate the release of its some 160 citizens newly detained this week.