The Minnesota State Fire Marshal is asking for the public's help in solving a series of church arson fires going back five years.
According to the fire marshal, 13 churches in eight Minnesota communities have been intentionally set on fire since 2012.
That includes last year's blaze that caused millions of dollars in damage to the 118-year-old St. Mary's Catholic Church in Melrose, as well as the historic Darling Church near Little Falls that was destroyed in March.
Authorities don't believe the church fires are related. They said houses of worship are vulnerable to fire because they're often in remote areas and unoccupied for long periods.
State Fire Marshal Bruce West said information from the public is critical to solving arson cases.
"Any little piece of evidence that a person may think is insignificant may be a significant break in a case for us," West said.
Anyone with information about the unsolved cases to call the Minnesota Arson Hotline at 1-800-723-2020.
Rewards of up to $5,000 are available for information leading to a conviction. Unsolved Minnesota church arson fires since 2012:
• Darling Historic Church on March 24, 2017, in Little Falls.
• St. Mary's Catholic Church on March 11, 2016, in Melrose.
• Abandoned church on Aug. 22, 2016, in Deer Creek.
• Church, Inc., building on Feb. 15, 2016, in St. Paul.
• Bethany Lutheran Church on June 13, 2014, in Minneapolis.
• Open Arms Assembly of God on Sept. 6, 2014, in St. Paul.
• Community Covenant Church on July 11, 2013, in Minneapolis.
• Faith Baptist Church on Aug. 26, 2013, in St. Paul.
• St. Elizabeth Catholic Church on May 28, 2012, in Isanti.