A power outage Sunday night darkened a large portion of Piscataquis County and part of Penobscot County.

There was no indication Sunday night what had caused the outage. Crews from Central Maine Power were on their way to make repairs, but according to a recorded message at the company’s emergency line, the source of the outage was not known as of about 8:15 p.m. Sunday.

The outage left customers in a large portion of the Piscataquis County without power. According to the CMP Web site, the outage affected customers from as far north as Rockwood and Lily Bay down into Greenville, Dover-Foxcroft and Guilford in Piscataquis County and as far south as Dexter and Corinna in Penobscot County.