ST. PAUL, Minn. (AP) — Agencies are increasing the reward for finding the arsonist who started the northwestern Minnesota wildfire that destroyed several homes in Karlstad.

The Minnesota Department of Natural Resources said Wednesday the reward has been increased to $8,500.

Fire investigators have determined the Karlstad fire was probably arson. And they say other recent fires in the area also are likely arson and may have been started by the same suspects.

The Karlstad fire started about 2 p.m. on Sept. 30 in Marshall County and destroyed 11 homes.

The most recent fire burned 25 acres on Oct. 15. That fire was located on the County Line Road northeast of Karlstad. Another fire on Sept. 9 burned 88 acres and was only about a mile from the start of the Karlstad fire.

(© Copyright 2012 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)