Amtrak says train service on its Borealis passenger rail line between St. Paul to Chicago will resume in part on Thursday, and in full on Friday, after being temporarily replaced with buses.

The railroad will use bi-level cars on the route in place of single-level cars pulled from the line Wednesday.

Amtrak’s daily Borealis service between St. Paul and Chicago was disrupted Wednesday, with buses replacing trains. The cause of the train cancellation was corrosion of passenger railcars used on the route. Amtrak made the announcement Wednesday morning and said the cancellation also affected its Downeaster, Hiawatha and Cascades service.