WINDSOR, ONT. -- Pelee Island ferry passengers who claim a medical exemption for wearing a mask, will soon have to prove it and show an approved medical certificate.

Owen Sound Transportation and Pelee Island Transportation Services is stiffening rules regarding the mandatory face mask requirements.

The new rule goes into effect Monday.

There are exceptions for children under two years of age or for people who need assistance to put on or take off a mask and are traveling without a support worker.

Violators could be banned from service for the duration of the season.