Up to 30 local residents armed with baseball bats attacked the trailers housing the workers on Tuesday. As a result of the assault, four of the Koreans were hospitalized with injuries.
A total of four locals were subsequently detained by police in connection with the attack.
There are some 10,000 North Korean workers in Russia. The majority of them are employed in the country's Far East, where they are closely monitored by North Korean security agents.
Routine attacks by skinheads and young gangs on foreigners and people with non-Slavic features have been reported across Russia in recent years. However, authorities have been generally reluctant to treat the attacks as race-hate crimes, portraying them instead as acts of hooliganism.