North Korean leader Kim Jong Un’s regime has stepped up surveillance of its officials and workers posted in locations abroad, following reports that multiple government officials recently defected to South Korea, according to a report. Under Kim, the North Korean government has enacted various punishments and executions of suspected dissidents.

North Korea “is making its high officials in other countries examine its workers,” a source within South Korea’s Ministry of Unification told Spanish news agency EFE, according to the Latin American Herald Tribune. Kim’s government was also “calling back some of its representatives posted abroad to verify what has been going on,” the source added.

An unspecified number of North Korean government officials have recently defected to South Korea, local reports said. The unnamed individuals purportedly fled North Korea to avoid Kim's "reign of terror," local media said. Aside from meetings with officials to assess the wave of worker defections, North Korean government loyalists will place the officials themselves under renewed scrutiny.

Earlier this week, a group of three North Korean sailors whose ship went adrift off the coast of South Korea stated their intention to defect to South Korea, the New York Times reports. South Korean government officials said they would accept the defectors, despite North Korea’s protestations. Days earlier, a North Korean scientist identified only as “Mr. Lee” fled to Finland and claimed he had evidence Kim’s government tested chemical weapons on the country’s own people, Newsweek reported.

Kim’s regime has been accused on several occasions of carrying out executions and purges of individuals seen as threats to the government’s security. Kim’s uncle Jang Song-Thaek, once one of the most powerful men in North Korea, was executed in December 2013, after North Korea’s government accused him of plotting a coup. Approximately 1,400 North Korean citizens were killed in public executions from 2000 to 2013, according to a Guardian report with data from the Korean Institute for National Unification.