Update, 4:20 p.m. Berkeley Fire Department Battalion Chief Paul Cavagnaro said the fire in Berkeley on Friday was confined to a 20-by-20-foot area of “pretty thick brush” in the midst of numerous homeless encampments where Bay Street goes over Ashby Avenue near the freeway.

Firefighters were dispatched to the area at 1:16 p.m., and Cavagnaro said the fire was likely out by around 1:30 p.m. There were no injuries.

Cavagnaro said that, despite an initial report that it may have been arson, no one witnessed anyone set anything on fire. He said many homeless people live in the area on both sides of the freeway, but that it’s difficult to estimate how many because the camps are “joined together.”

“We’re not sure how many people are living in the bushes,” he said.

Update, 3:55 p.m. Berkeley Police Lt. Alyson Hart said the fire was limited to property damage at two homeless camps. She said the fire may have been either arson or an accident, and that no one is in custody. Berkeleyside will follow up with the Berkeley Fire Department for additional information.

Original story, 1:50 p.m. Berkeley authorities are responding to a fire near Ashby Avenue and Interstate 80, which is backing up traffic in the area.

Community members in West Berkeley reported the smell of smoke and the sound of loud firetrucks just before 1:30 p.m. near Ashby and Ninth Street.

Authorities briefly closed the Ashby onramps to Interstate 80, in both directions, at 1:38 p.m.

A first responder described the cause of the fire over the scanner, at 1:42 p.m., as arson, and said someone had been detained in connection with the incident.

Subscribe to the Daily Briefing Don’t miss a story. Get Berkeleyside headlines delivered to your inbox. Don’t miss a story. Get Berkeleyside headlines delivered to your inbox.

“This was arson and they have the individual up here,” he said.

Initial reports from the CHP described the incident as a grass fire, but Berkeleyside has asked the Berkeley Fire Department for confirmation and additional information.

Responders said shortly before 2 p.m. that the incident took place on Caltrans property, and asked for a city arborist to respond to the scene to help remove a large tree in the area affected by the fire.

The first report to the California Highway Patrol came in at 1:25 p.m., when someone reported “lots of flames and smoke” seen from Interstate 80 at Ashby.

The Amtrak train tracks were briefly closed during the investigation and response, but were cleared to reopen at 1:47 p.m., according to scanner traffic.

Berkeleyside will update this post if more information is provided.

Read more about fires in Berkeley in past Berkeleyside coverage.

Do you rely on Berkeleyside for local news? Support independent journalism by becoming a Berkeleyside member for $5 a month or even less, or by making a one-time donation.