Police and firefighters responded to Channing Way and Acton Street in Berkeley for a working fire shortly before 2 p.m. Monday.

Sgt. Andrew Frankel, Berkeley police spokesman, said the fire was contained to a rear in-law unit and a small outbuilding behind a single-family home in the 2300 block of Acton Street.

This story was updated due to the developing nature of events

Numerous people called in reports of the fire at 1:56 p.m. Frankel said first responders got to the scene and began evacuating nearby homes, as well as the single occupant of the home where the fire broke out. At one point, the fire was classified as “two-alarm,” triggering calls for mutual aid from other agencies because there was concern the fire might spread. But that request ultimately was canceled. The Albany Fire Department did respond to help, and remained on scene as of about 3:20 p.m.

Assistant Berkeley Fire Chief Keith May said, as of nearly 3:30, the cause was still under investigation, and no damage estimate was available yet. No injuries were reported.

A neighborhood resident shared photographs of the block on Twitter at about 2:30 p.m., writing, “Our amazing BFD made quick work of what had been a terrible fire 15 minutes ago.” The same resident initially reported, just after 2 p.m., a “HUGELY energetic fire, Channing & Acton. BPD, BPD just arriving.” Said another, “Looks like a big fire in south central Berkeley. Thick smoke billowing up.”

Wrote Berkeleyside reader Alexander Sinclair Merenkov shortly after 2 p.m., “Ash now starting to fall in downtown.” Some homes on Acton were evacuated, and the fire was said to be spreading into the backyard where the fire began, according to unconfirmed scanner traffic reviewed by Berkeleyside.

My nieghbor's house in Berkeley–Channing and Acton. Very sad and close to home. Thank you @BerkeleyFD @berkeleyside pic.twitter.com/AB5t3V9nmF — Rachel Sklar (@Sklar_R) October 3, 2017

@berkeyside fire at Acton https://t.co/SbqvU1E7oC — Daniel McPartlan (@dancalbear) October 2, 2017