Japan reported its first case of the omicron variant Tuesday, less than a day after the country imposed sweeping restrictions on inbound travel to prevent the new strain from spreading domestically.

Health minister Shigeyuki Goto told reporters Tuesday evening that genomic screening had detected the variant in a male Namibian diplomat in his 30s who had landed in Tokyo on Sunday traveling from Namibia — one of the nine African countries where omicron cases had initially been reported.

The 71 passengers aboard the same plane as the individual are all being treated as possible contacts, Goto said, and will be quarantined for 10 days at a government-designated facility, tracked remotely through a GPS-enabled application operated by the health ministry and tested for COVID-19 once every two days while in isolation.