SAN FRANCISCO—San Francisco police searched Sunday for a man suspected of throwing a flammable liquid at his girlfriend and severely burning her.

Officer Carlos Manfredi said witnesses in the city's Bayview District reported hearing the woman screaming. She was taken to a hospital burn unit with life-threatening injuries.

Investigators believe her attacker was 22-year-old Dexter Oliver.

Manfredi said Oliver had a "dating relationship" with the woman, but he did not know the circumstances that led to the attack.

The victim's sister told KGO-TV that Oliver doused his girlfriend with gasoline and lit her on fire during an argument at a nearby Laundromat.

Precious Craig said most of her sister's face was burnt, and that the family expects her to recover.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

Police searched Sunday for a man suspected of throwing a flammable liquid at his ex-girlfriend and severely burning her.

Witnesses in the city's Bayview District reported hearing the woman screaming a little after noon, Officer Carlos Manfredi said.

She was taken to a hospital burn unit with life-threatening injuries. Her name was not released.

Investigators believe her attacker was 22-year-old Dexter Oliver and released a photo of him. Manfredi said Oliver had dated the woman, believed to be in her 20s, but he did not know the circumstances that led to the attack.

He said investigators have not determined the type of liquid thrown at the woman. They went to the woman's home, which had a broken window, and a nearby Laundromat to question witnesses.