A rampaging stranger broke a 36-year-old Brisbane woman’s nose, knocked out her tooth and cut her head at a Daly City car wash, authorities said.

The victim’s daughters, ages 4 and 6, witnessed the attack from the back seat of their mother’s car, police said. Authorities are looking for the assailant, described as a 5-foot-5, 160-pound woman in her 30s.

The episode happened around 7:50 p.m. July 29 at the Shell gas station on Hillside Boulevard.

The victim, who was not identified, told police she started driving into the gas station’s car wash when the vehicle in front of her began driving back and forth, nearly slamming into her car.

The driver ahead then parked in the car wash and got out, prompting the victim and others in line to start honking, police said.

The erratic driver, now out of her car, flew into a rage and began hitting the victim’s vehicle with her hands and her phone, police said.

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After the woman in the car lowered her window, police said the assailant grabbed it with both hands and slammed it down. With the window open, she began throwing punches, police said.

The attacker grabbed the victim’s cell phone, saying, “You’re not going to call police,” authorities said.

The victim got out of her car, and the assailant grabbed her by the hair and begin beating her, police said. The attacker landed several punches before pushing the woman to the ground and chucking the cell phone at her, police said.

The assailant then got in her car and took off, police said.

Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky