Amtrak is in the midst of canceling five runs of the Empire Builder between St. Paul and Spokane, Wash., citing lengthy delays for hundreds of passengers because of heavy freight traffic along the line and recent extreme cold weather.

The cancellations began Wednesday and will continue through Sunday, said Marc Magliari, a spokesman in Chicago for the passenger rail service.

Eastbound runs from Spokane to St. Paul were canceled for Wednesday, Friday and Sunday. Westbound service was canceled Thursday and will be scrapped Saturday.

Magliari said the cancellations were necessary because trains were running so far behind schedule. The hope is to get the schedule “back in cycle,” he said.

Hundreds of ticketholders on each run were being notified and helped in making new arrangements, he said.

Service is unaffected west of Spokane to Seattle and Portland, Ore., and between St. Paul and Chicago, the spokesman said.

Magliari said “extreme temperatures coming earlier than usual” are partly to blame. Ice and snow have built up on the tracks’ switching mechanisms, and hoses and electrical connections on the trains have broken down under the wintry conditions, he added.

The other major factor has been a surge in congestion by freight trains along the tracks, which are owned the BNSF freight carrier.

Amtrak hopes to have its schedule “back into the proper rotation before the week of December 25th,” Magliari said, when passenger demand is expected to increase.

BNSF spokeswoman Amy McBeth said the rail company also is tackling weather-related complications along with the challenges of increased demand on its northern corridor tracks.

McBeth said improvements in several sectors of the national economy — agriculture, retail, crude oil and automotive — have created a surge in train traffic that has not been seen since 2006.

“We’re investing heavily in [increasing] our capacity” in areas of maintenance and expansion to “help with fluidity and increase capacity,” she added.

Metro Transit’s Northstar line connecting downtown Minneapolis and Big Lake to the northwest also has been affected by the heavy freight rail traffic, said transit spokesman John Siqveland, noting that three of five morning trips in were delayed Dec. 5.