Health officials say two cases of diphtheria have been diagnosed in the area of Onion Lake Cree Nation in Saskatchewan.

A medical health officer for Indigenous Services Canada recently sent a notice to the chief of Onion Lake Cree Nation, near the Saskatchewan-Alberta boundary, informing him that the two cases were diagnosed in the last month.

The notice says people may be at risk of infection because the vaccination rate for diphtheria in the Onion Lake area is below the desired target.

The First Nation's Director of Operations Philip Chief said one confirmed case was in Onion Lake while the other was in the surrounding area.

Chief said he doesn't have details but it's concerning.

He said staff have been informed and will be asking members to ensure they are updated on their immunization and booster shots.

Health officials say diphtheria is a rare but infectious disease that is preventable through vaccines.

Symptoms include a sore throat, fever, and swollen glands in the neck.

Complications from diphtheria can be deadly. The Centres for Disease Control and Prevention says even with treatment, one in 10 diphtheria patients die.