Russian President Vladimir Putin ordered the Federal Security Service (FSB) to track down Russian citizens who are fighting in Ukraine's military or pro-Kyiv militias in comments during a meeting of the FSB's board on March 19.
The Freedom of Russia Legion, the Siberian Battalion, and the Russian Volunteer Corps, consisting of Russians who fight for Ukraine, launched cross-border incursions into Russia's Belgorod and Kursk oblasts on March 12, allegedly resulting in clashes with Russian forces in several settlements.
There are other units of Russians, such as the primarily Chechen Dzhokhar Dudayev and Sheikh Mansur battalions, that have also been fighting for Ukraine.
Putin said that all such Russians must be tracked down and "punished...without any statute of limitations, wherever they may be located."
In a historical parallel common in Putin's rhetoric, he also compared Russians fighting for Ukraine to the Russian Liberation Army (also known as the Vlasov Army), who fought alongside Nazi Germany against the Red Army in World War II.
Russian security services have a long history of hunting down perceived traitors abroad, including engaging in targeted assassinations.