SEOUL (REUTERS) - North Korean leader Kim Jong Un has made his second public appearance this week to oversee military drills, despite concerns about the possible spread of the coronavirus.

Mr Kim guided the spot drills on Thursday (March 12), which included a firing competition by artillery units to evaluate their combat readiness, the official KCNA news agency said on Friday.

North Korea, sandwiched between China and South Korea, has not confirmed any cases of the coronavirus but has stepped up border checks and imposed quarantine measures.

Photographs published by KCNA showed Mr Kim watching the artillery drills without any protective gear, unlike all the aides accompanying him, who were wearing identical black masks.

Mr Kim similarly avoided wearing any kind of protection when he watched missile tests last week and on Monday. Those tests were the first by North Korea in three months.

On Monday, North Korea flew dozens of diplomats out of the country to Russia, including the staff from Germany, France and Switzerland which had closed their missions amid coronavirus concerns.

As well as the border checks, any foreigner from countries that have reported a case of the virus is required to spend 30 days in quarantine.

KCNA said in a separate dispatch that the country was intensifying its prevention efforts.

"All workers are strengthening awareness-raising campaigns about the global spread of the disease and prevention and treatment policy so that no one lowers their guard because the outbreak has not occurred in our country," KCNA said.

Until the military exercises over the past week, Mr Kim had not been seen in public for more than three weeks, barring a brief appearance to pay tribute to his late father, Kim Jong Il, on the latter's birthday anniversary.