July 1 (UPI) -- China's National Immigration Administration conducted large-scale exercises at the China-North Korea border to guard against "unconventional" security threats.
The Chinese government agency posted to its WeChat account on Wednesday a video of training it conducted in Jilin Province, home to China's largest ethnic Korean-Chinese population.
China and North Korea share an 880-mile border, and about 750 miles of the border is in Jilin Province.
On Wednesday, Beijing's immigration agency did not mention specific training locations. The uploaded video showed armed Chinese police officers entering a building with a police dog and subduing "criminals" during the exercise.
Jilin Province has said it is arresting organized crime rings that conduct illegal gambling operations, according to South Korean news agency Yonhap.
Provincial authorities have said they would arrest Chinese nationals who have been charged with running gambling operations in North Korea. Authorities have offered rewards for informers who have intelligence on crime rings, Yonhap reports.
China's immigration bureau has also conducted similar training in other parts of the country, including Shanghai, Yunnan Province, and in Xinjiang, home to China's Uyghur population. The agency has said 2,100 officers trained nationwide, the largest exercise ever conducted after 2018, when China introduced reforms affecting the People's Armed Police Border Defense Corps.
China's border with North Korea shuttered following the declaration of a national emergency in the North in the wake of the coronavirus pandemic.
The closure of the border could be affecting migration out of North Korea, Seoul's unification ministry said.
"The biggest reason behind the decline [in defections] is that the national borders of these countries were closed after the outbreak of the coronavirus and cross-border movement became difficult," said ministry spokesman Yoh Sang-key, according to the Financial Times.
The number of North Koreans in China range from 50,000 to 200,000, according to the report.