OAKLAND — Firefighters rescued a father and his toddler son on Thursday night from an apartment complex fire in Oakland’s School neighborhood, officials said.

The blaze erupted in another unit, and father and son were uninjured.

One person was injured in the blaze at the three-story complex in the 3000 block of Capp Street and at least 20 residents were displaced, officials said.

The fire started about 8:10 p.m. Thursday in an apartment at the 17-unit building, located in the School neighborhood south of Interstate 580 near the Dimond district.

While firefighters were working to extinguish the blaze and evacuate everyone safely, a resident yelled that there was a baby inside an apartment, fire department spokesman Michael Hunt said.

One probationary firefighter grabbed a ladder from an engine and worked with his crew members to extricate the father and child, who was about 2-years-old, out of a top floor unit window along the side of the building, officials said. They were brought down to safety before extensive smoke that could injure them spread there, Hunt said.

“All of the responding crews worked efficiently and effectively to extinguish the fire while ensuring the tenants from each of the floors were able to get out of the building safely,” Hunt said. “Really strong work by everyone involved in this response.”

The fire was under control in about 30 minutes and was contained to the apartment where it started on a lower floor, although other units suffered water and smoke damage.

One resident was treated at the scene for a minor leg injury before being transported to a hospital, Hunt said.

The Red Cross was helping to provide shelter to at least 20 people and two dogs that were displaced, fire officials said.

The cause of the fire remained under investigation Friday.