PORTLAND – Portland police are investigating threats against Democratic congressional candidate Chellie Pingree.

Police would not go into specifics about the nature of the threats but said they were made in anonymous mailings sent to Pingree in recent weeks.

Deputy Police Chief William Ridge said a detective has been assigned to the investigation. The state Attorney General’s Office is coordinating with Portland police.

Pingree, a former state senator, finished first among six candidates in the June 10 Democratic primary in the 1st Congressional District. She will face Republican Charlie Summers in November.