VANCOUVER -- More flights have been added to the list alerting passengers who arrived at British Columbia airports of potential exposure to COVID-19.

The BC Centre for Disease Control says passengers on a Delta flight on July 29 from Seattle to Vancouver and a flight from San Francisco to Vancouver on Aug. 1 may be at risk.

All travellers from outside Canada must self-isolate for 14 days, which can limit the possible spread of the illness from international flights.

But the centre says passengers on a WestJet flight from Calgary should also self-monitor for symptoms for the next 14 days.

It says a person with COVID-19 was onboard flight 538 on July 29, affecting rows 5 to 11.

B.C. Transportation Minister Claire Trevena sent a letter to her federal counterpart earlier this week asking for help in getting airlines to provide more complete information on passengers to aid contact tracing efforts.