The Alexander Mountain fire burning on more than 9,600 acres in Larimer County was human-caused and fire officials are looking for suspects, according to the U.S. Forest Service.

Forest Service wildland fire investigators are working with the Larimer County Sheriff’s Office to investigate the cause of the 9,668-acre fire burning west of Loveland.

Officials previously said signs of human activity were discovered near the fire’s origin, and on Friday announced investigators believe the fire was human-caused.

“This is an active, ongoing investigation, and investigators from both agencies are working together closely to follow all leads,” fire officials said in a Friday news release.

Investigators are asking anyone with information about who or what could have started the Alexander Mountain fire to call the Forest Service Law Enforcement Tip line at 303-275-5266. Photos, videos and typed statements can also be uploaded online.

Fire officials are specifically interested in information about anyone who was in the area east and below the peak of Alexander Mountain and in photos of the fire between 10:30 a.m. and 11:15 a.m. on July 29, the news release stated.

This is a developing story and may be updated.