Metro Transit says buses are replacing all Northstar trains Tuesday morning because mechanical problems with two freight trains have blocked the tracks.
Northstar Link service will pick up in Big Lake, Elk River and Ramsey.
Metro Transit buses will pick up at Anoka, Coon Rapids and Fridley.
An update from BNSF Railway spokeswoman Amy McBeth:
"We have had mechanical issues early today with two different freight trains. Very cold temperatures create air brake problems. Until air flow issues are addressed trains cannot move safely. This has resulted in delays".
The freight trains are blocking the BNSF tracks between Big Lake and Elk River.