PORTLAND (AP) — Amtrak Downeaster passenger rail service between Boston and Maine has been delayed or canceled this week so damaged tracks can be repaired.

The Northern New England Passenger Rail Authority, which manages Downeaster service, said inspectors determined that harsh winter weather and heavy snow melt had destabilized the ground under about 27 noncontiguous miles of track between Freeport and Boston.

The Portland Press Herald (http://bit.ly/1fOSPG0 ) reported that two runs have been canceled for the week — the 686 train that leaves Portland at 2:35 p.m. weekdays and arrives in Boston at 5:05 p.m., and the 683 train that leaves Boston’s North Station at 11:35 a.m. weekdays and arrives in Portland at 2:05 p.m.

All other runs are expected to take an average of 35 to 45 minutes longer than normal.