SEOUL, South Korea (AP) — A special North Korean flight carrying presumably dozens of diplomats and other foreigners arrived in Russia's Far East on Monday as the country tightens its lockdown intended to fend off the coronavirus.

North Korea has not publicly confirmed a single case of the COVID-19 illness, but its state media have reported thousands of people have been quarantined as part of strict prevention measures.

Seemingly dozens of passengers, most of them masked and some accompanied by children, lined up at Pyongyang International Airport. North Korean health workers wearing white protective suits scanned them for fevers.

It wasn’t immediately clear how many were flown out to Vladivostok. The North lifted a monthlong quarantine on foreign diplomats based in Pyongyang on March 2, allowing them to leave the country if needed.

The website of Vladivostok International Airport showed Air Koyro Flight 271 arrived at 10:49 a.m. local time.

Colin Crooks, the British ambassador to Pyongyang, tweeted: "Sad to say farewell this morning to colleagues from German Embassy and French Office #NorthKorea which are closing temporarily.” He said the British embassy would remain open.

The French Foreign Ministry last week confirmed it plans to temporarily close its cooperation office in Pyongyang.

“North Korea has taken drastic containment measures since the end of January which notably concern foreign representative offices and seriously impede the functioning of the French Cooperation Office in Pyongyang,” the ministry said in a statement.

The North has called its anti-virus campaign a matter of “national existence” while banning foreign tourists, shutting down nearly all cross-border traffic with China, intensifying screening at entry points and mobilizing health workers to monitor residents and isolate those with symptoms.

Many experts say North Korea is highly vulnerable to infectious diseases due to its chronic shortage of medical supplies and outdated health care infrastructure.

State media reports suggest about 7,000 North Koreans have been quarantined, 3,000 in North Phyongan province which borders China, 2,420 in South Phyongan province and 1,500 others in Kangwon province.