Federal authorities have confirmed that an Air France flight travelling from Paris to Detroit was redirected to Montreal on Wednesday following an Ebola scare.

The diversion was triggered by current US flight restrictions linked to the Ebola outbreak in Central Africa, after it emerged that one of the passengers had originated from the Democratic Republic of Congo.

Air France had permitted the passenger to board “in error on a flight to the United States,” according to a statement from a US Customs and Border Protection spokesperson.

The spokesperson added that the passenger “should not have boarded the plane” due to “entry restrictions put in place to reduce the risk of the Ebola virus.” It remains unclear, however, when the individual had last been in Congo.

A Public Health Agency of Canada Quarantine Officer assessed the passenger and, according to the agency, found the individual to be showing no symptoms, enabling them to be placed on a return flight to Paris.

The Africa Centres for Disease Control and Prevention formally confirmed the ongoing Ebola outbreak in eastern Congo on 15 May. As of Wednesday, the World Health Organisation had recorded at least 600 suspected cases and 139 suspected deaths connected to the virus.

Health authorities have indicated the outbreak is caused by the Bundibugyo strain, for which no approved vaccines or treatments are currently available. The flight was rerouted at the request of U.S. authorities, according to Air France, which stressed that there was “no medical emergency on board.”

Deborah Mistor, a passenger on the flight, told CBS News: “The flight attendants all had masks on, which no one had prior to the announcement. So it was really concerning, like, what is going on here? Why are we not being allowed to land?

“I think enough people must have been questioning what was going on because 30 minutes later, he came back on and said that he wanted to confirm that there was nothing wrong with the plane, there were no technical difficulties, that it was strictly because of U.S. authorities not allowing us to land in the U.S.,” Mistor told CBS News.

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