Seoul, Jul 30 (IANS): North Korea's No. 2 leader visited Kaesong to inspect anti-coronavirus efforts, state media reported on Thursday, after leader Kim Jong-un sealed off the border city over COVID-19 fears following the return of a defector from South Korea.

On Sunday, North Korea said that it has put Kaesong on lockdown, claiming that a "runaway" defector suspected of COVID-19 infection recently returned from the South.

Seoul later said a North Korean defector is believed to have swan across the border but doubted he had contracted the virus, reports Yonhap News Agency.

Choe Ryong-hae, president of the Presidium of the Supreme People's Assembly, visited Kaesong and inspected emergency anti-virus efforts underway in the city, according to Pyongyang's Korean Central News Agency (KCNA).

Choe held a meeting with local officials and instructed them to make sure that food and medical supplies are provided to residents in need and that disinfection and other anti-virus measures should be strictly carried out as required, KCNA added.

His trip to Kaesong appears aimed at emphasizing the importance of antivirus efforts and urging people to stay vigilant amid growing fears that the coronavirus could break out in the border town and spread to the rest of the country.

State media, however, said Thursday there has been no COVID-19 infection in North Korea, the first mention that the country remains virus-free since Pyongyang put Kaesong on lockdown following the return of the defector showing virus symptoms.

"There has not been even a single case of new coronavirus infection so far in our country," Yonhap News Agency quoted Rodong Sinmun, the official daily of the North's ruling party, as saying in an article.

It is still unclear whether the report means the defector with virus symptoms eventually tested negative for the disease or not.

State media earlier said the defector has been put under "strict" quarantine after several medical checkups produced an "uncertain result".