Eventually , due to the negative publicity , and pressure from U.S.-based customers due to the 2006 North Korean nuclear test and the resulting sanctions , many companies stopped employing North Korean guest workers , and the Czech Republic stopped issuing employment visas to them . However , even after the existing visas expired , 144 North Koreans continued to work in the Czech Republic . Media reports speculated that the remaining North Koreans may have been granted individual exemptions by immigration officials , or had been able to obtain other types of visas
2006 North Korean nuclear test
2006 North Korean nuclear test
Koreans in the Czech Republic