The decision was made after the Canadian army learned that someone on the Trenton military base in Ontario, where the plane took off Thursday, had tested positive for COVID-19, according to department spokeswoman Jessica Lamirande.

The person in question could have come in contact with the 70 passengers and crew members on the plane, she said.

"The health and well-being of our members, and that of our Allies and partners in Latvia, is a priority," Lamirande told AFP on Sunday.

"As such, the decision was made to return the aircraft en route, rather than land in Latvia, to avoid the possible risk of spreading the disease."

The soldiers will quarantine for 14 days at the Trenton base before being redeployed, Lamirande added, noting that the incident will not have any major effect on Canada's mission in Latvia.

Canada has about 540 soldiers deployed in Latvia, where the North American nation has been leading a NATO battle group since 2017.