Police searched an area of the garment district in Los Angeles for more than an hour on Friday after a caller reported seeing a man with a gun in the busy shopping area.
Officers were called to an area of 11th Street at around 10:35 a.m., police said.
"It appears that the suspect brandished a gun at a passerby," Officer Wendy Reyes said. She had no other details.
The report could not immediately be confirmed and there were no reports of shots fired or any victims, but officers responded out of caution, police said.
Police did not immediately evacuate the area. It was taking time to search among the many small shops and streets thronged with shoppers, Detective Gus Villanueva said.