SOUTH PORTLAND — A 39-year-old South Portland woman was killed Saturday evening when she was struck by a southbound Downeaster train about one mile south of the Portland Transportation Center.

Nyla J. Howard was hit by Train 698 at 6:55 p.m., according to an email from Amtrak spokeswoman Kimberly Woods. Woods said Howard was trespassing on the tracks.

None of the 68 passengers on the train were injured, according to Woods. The crew asked to be relieved, and another crew was brought in to replace them.

Train 698 resumed service at 9:20 p.m., and it operated about two and a half hours behind schedule, according to Woods. Train 695, traveling northbound to Brunswick, also was delayed two hours.

The Amtrak Police Department is investigating the incident.