MEDWAY -A fire that damaged a 1 1/2-story house Monday while the resident was being held at Penobscot County Jail on a drug charge was arson, a State Fire Marshal’s Office investigator said Tuesday.

Ed Archer, a senior fire investigator with the State Fire Marshal’s Office, determined the fire had been set at 933 Medway Road after he investigated the site for about two hours, said his supervisor, Sgt. Tim York.

Medway Fire Chief John Lee said he called for Archer because it appeared no one was home when a passer-by called 911 about 5 p.m. Monday to report the fire and because firefighters could not immediately determine what started the blaze.

East Millinocket Police Chief Garold Cramp, whose department covers Medway, was at the scene Monday evening, but said he was there only to provide traffic control near the house, which is opposite Lone Duck Drive.

Cramp could not be reached for comment on Tuesday. The Maine State Fire Marshal’s Office is working with East Millinocket police, who cover Medway, on the investigation, York said.

The arson is not yet believed to be connected to any other arson or suspicious fire within the Katahdin region, York said.

About 26 East Millinocket, Mattawamkeag and Medway firefighters went to the scene of the fire on Monday. The flames burned into a second-floor bedroom, and some smoke and water damage occurred on the second and first floors before the fire was doused.

The fire apparently began in the corner of a utility room attached to the home before burning up into the adjoining second-floor area, Lee said.

Neighbors said the resident, whose name is being withheld, rented the home and lived there with her boyfriend until her conviction and said that other family members occasionally visit the house, possibly to tend to her pets. It was not clear whether any pets were harmed in the fire.

No firefighters were injured battling the fire.