A Los Angeles police officer’s pistol was stolen Thursday night during a fight with a woman, who attacked him with his handcuffs as protesters flooded downtown to decry the election of Donald Trump.

Around 10:30 p.m., undercover officers noticed a crowd of roughly 20 people break off from the hundreds protesting against Trump and move back toward LAPD headquarters, according to an official with knowledge of the incident. The official, who spoke to the Los Angeles Times on condition of anonymity, was not authorized to discuss the case.

The confrontation began when undercover officers attempted to arrest a man who was spray-painting near the building, the official said. A woman came up and complained before snatching one officer’s handcuffs and striking him in the head several times, the official said. Natalie Araujo was booked on suspicion of assault with a deadly weapon after she was treated at a hospital for unknown injuries, according to LAPD Officer Tony Im.

After the struggle, Im said, the officer noticed his gun was missing. Neither the weapon nor the handcuffs used in the attack have been recovered.