A series of small fires broke out Sunday night at the massive Mill & Main complex in downtown Maynard and investigators say accelerants were found in three locations.

Eight fires broke out in stairwells and office suites within building 2 at the 1.1-million-square-foot former mill complex, which is owned by Waltham-based Saracen Properties and Artemis Real Estate Partners. The 6-story building 2 contains 152,982 square feet of commercial space built in 1864. The fires reported at 6:55 p.m. did not trigger sprinkler systems and damage was minor, the Maynard fire department said in a press release. State police canine units found evidence of accelerants used in three areas.

The fires are being investigated by Maynard fire and police departments and the State Police fire and explosive investigation section.

“It is a sprawling property. I don’t know if it was kids or a disgruntled employee,” Ted Saraceno, president of Saracen Properties, said in a statement. “We’re taking it seriously and so is the town. We’re controlling access and doing all the things we’re supposed to do.”

The former woolen mill complex was converted into office space for the Digital Equipment Corp. headquarters in the 1980s and later became a multi-tenant complex called Clock Tower Place including the headquarters of online job recruiter Monster.

Monster relocated to Weston in 2014 and Saracen acquired the complex at a public auction in 2015.

Stratus Technologies last week moved into its new 102,321-square-foot headquarters in a relocation from 116 Powder Mill Road in Maynard.

The owners have announced a $20 million capital improvement program that will include new outdoor plazas, common area renovations, a pedestrian bridge spanning Mill Pond and a Battle Creek Brewing pub that is scheduled to open this summer. CBRE/New England was named leasing agent in March for approximately 650,000 square feet of available space.