North Korean leader Kim Jong Un has lifted a three-week lockdown in the city of Kaesong after a suspected case of the novel coronavirus there, state media reported on Friday, without saying if it had been confirmed or was a false alarm.

North Korea has not reported any cases of the coronavirus and Kim told a ruling party politburo meeting on Thursday the country had to be vigilant and decline any offer of foreign aid to battle flooding to keep the virus at bay.

“The worsening global situation on the malignant virus requires us not to allow any outside aid for the flood damage but shut the border tighter and carry out strict anti-epidemic work,” Kim said in comments carried by the KCNA.

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Authorities locked down Kaesong, on the border with South Korea, and declared an emergency in the area last month after a North Korean who had defected to the South slipped back into the town.

State media said the man had shown coronavirus symptoms. The World Health Organization said later test results on him were inconclusive.

Kim told the politburo that coronavirus prevention measures had stabilised the risk in the area but the border had to remain shut to any help in response to hardships brought by unusually long monsoon rains.

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Floods have swamped farmland and inundated or destroyed 16,680 houses and 630 public buildings, and damaged bridges, railroads and power plants, KCNA said.

During the meeting, Kim appointed Kim Tok Hun, a relatively young economic policymaker who served as a deputy cabinet premier, as premier to steer his campaign for a self-sufficient economy amid international sanctions.

The politburo also elected Ri Pyong Chol, a former air force commander who has quickly climbed the leadership ladder under Kim for his work to develop nuclear missiles, as a full member of the powerful body.

Ri previously directed the Munitions Industry Department, which oversees ballistic missile development.