Portland fire investigators are looking into a rash of fires at homeless camps over the past two months, an agency spokesman said.

Investigators don't have any leads or suspects in the approximately 15 to 20 fires, the spokesman said, nor do they know whether they're connected.

But, he said, the fires are "suspicious enough they want to get as much info as possible."

Investigators don't know how many of the Portland homeless camp fires are arsons, Lt. Rich Chatman, a Portland Fire & Rescue spokesman, said Thursday. The investigators had been comparing notes in recent days when they noticed a pattern was starting to develop, he said.

The agency is sifting through all the small- to medium-sized fires from the past couple months, and reviewing files and incident reports of applicable cases to see whether there are any consistent findings, Chatman said. Fire officials are hoping to publicize their findings next week, he said.

Fire and police officials are also working to set up a Crime Stoppers tip line regarding homeless camp fires, Chatman said.

"Without the public's help, we have very few leads to work with," he said.

The homeless camp fires haven't been concentrated in any particular part of the city, he said. Some of the more recent ones have been on the inner east side, Chatman said, and there have been some in north and inner Southeast Portland.

No serious injuries have been reported in connection with any of the fires.

Chatman said lighting a fire at a homeless camp is comparable to doing so at, say, an apartment or condominium. It's a serious crime, he said, because people sleep at the camps.

Authorities pressing charges for people suspected of lighting such fires would consider the serious harm or death the fires could have caused, he said.

"You're putting people's lives at risk," he said.

-- Jim Ryan

jryan@oregonian.com

503-221-8005; @Jimryan015