PORTLAND, Ore. -- Portland police officers were stationed at Southwest 14th and Montgomery avenues for more than two hours Friday afternoon, issuing “trespass warnings” to homeless campers on a small stretch of Oregon Department of Transportation land that runs along Interstate 405.

It was the same stretch that caught fire hours earlier.

“I could just see the burned out spot where all their belongings, tents, old car seats, whatever, were burned down to the springs,” said a camp’s neighbor, who only wanted to be identified as Laura.

Portland Fire & Rescue confirms the fire started around 9 a.m. along the southern stretch of the camp. Investigators don’t know what caused it.

Campers told KGW it could have been anything from a discarded cigarette to an intentional attack.

Neighbors, like Laura, said it confirmed some of their worst fears.

“If there's one huge reason why you wouldn’t want this kind of camp here, it’s because they would catch the rest of the buildings on this street on fire in the heat of summer,” she said.

Neighbors said, for months, the problem has been crime. A few have dealt with in-person threats.

Many more have found their car windows smashed and their garbage cans ransacked.

“It's a balance here between wanting to be compassionate and wanting comfort and safety in your own neighborhood,” said Lance Pound.

Neighbors said they’ve called police, telling them about the problems and the camp, but they say most of the time, no one is arrested and the camp remains untouched.

Some blamed both results on ODOT, who’s legally required to give campers 10-19 days warning before ordering them to move from their property.

But Sgt. Randy Teig of the Portland Police Bureau said Friday that’s not the issue.

“Our hands are not tied,” said Tieg said. “If we can prove a crime we'll make the arrest… but we have to have evidence.”

Sgt. Teig said the problem often lies in vague reports, noting most callers can't pin crimes on a specific person, and while police can break up camps that, as a whole, present threats to public safety, they can't arrest everyone on mere suspicion of singular crimes.

“It seems like a logical course of events,” he said. “You know, ‘There’s a camp here, and my car window is broken. I didn’t have a car prowler until they showed up.’ That might seem logical, but it doesn’t meet the standards for us to arrest people, and it’s frustrating.”

Sgt. Teig recommended, if possible, calling with specific descriptions of people and of any troubling events you see going on in the camp.

Friday, police confirmed they got a high volume of calls about the camp at Southwest 14th and Montgomery. Callers reported the fire and a cut hole in the ODOT fence.

One person even reported seeing a specific camper injecting, what looked like, heroin into their arm in broad daylight.

Sgt. Teig added police are launching new programs, courtesy of a boost in funding allocated by Mayor Ted Wheeler.

He said officers are now working extra shifts two days a week, walking and riding ATVs through major homeless camps and checking for warrants.

Since June, he said, PPB officers have arrested 40 people along ODOT’s multiuse bike path, near Southeast 92nd Avenue and Woodstock.