North Korea has reported what it describes as the country’s first suspected case of coronavirus.
State media said a person who defected to South Korea three years ago last week returned across the demarcation line with Covid-19 symptoms.
Leader Kim Jong-un held an emergency meeting with top officials, imposing a lockdown in the border city of Kaesong.
North Korea, a secretive state, had previously not reported any virus cases – but analysts said this was unlikely.
“An emergency event happened in Kaesong city where a runaway who went to the south three years ago – a person who is suspected to have been infected with the vicious virus – returned on 19 July after illegally crossing the demarcation line,” news agency KCNA said.
At Saturday’s politburo meeting, Mr Kim was said to have ordered a “maximum emergency system” to contain the virus.
Mr Kim also launched an investigation into how the person had managed to cross the heavily fortified border, KCNA added, warning those responsible that “a severe punishment” would be administered.
On Sunday, a South Korean military official said there were “high chances” that an individual had illegally crossed into the North and that an investigation had been launched, according to Yonhap news agency.
North Korea closed its borders and put thousands of people in isolation six months ago, as the virus swept across the globe.
Earlier this month, Mr Kim hailed his country’s “shining success” in dealing with Covid-19.