A quarantine mishap over novel coronavirus procedures occurred at Narita International Airport involving 92 passengers and crew members of an All Nippon Airways flight that arrived from Chicago, the health ministry said Friday.

The ANA flight arrived at Narita Airport in Chiba Prefecture on Thursday, when the nation’s entry restrictions related to the coronavirus started to cover travelers from the United States. But quarantine officers let the 76 passengers and 16 crew members enter the country without asking them to take necessary measures, such as self-quarantining in their homes or designated facilities for two weeks and avoiding the use of public transportation, the ministry said.

The error occurred because the officers miscalculated the time difference between Japan and Chicago, according to the ministry.

The ministry will ask ANA for the passenger and crew list so it can identify the 92 people. It will then ask those people to self-quarantine and monitor their health for signs of infection.

The quarantine mistake “should have never happened,” health minister Katsunobu Kato said.