Police confirmed there was no shooting at The Shops at Montebello.
Twitter video showed at least four suspects smashing the glass at a kiosk inside the mall, grabbing several items and running out the door.
The sounds of the shattering glass loudly echoed through the mall and may have been mistaken for gunfire.
Several people posted on Twitter that they believed there was an active shooter.
There is NO ACTIVE SHOOTER at the Montebello Mall... suspect smashing glass with a hammer only @MontebelloPD— LA County Sheriffs (@LASDHQ) December 24, 2019
The mall was expected to remain closed Monday night.
Police said anyone who evacuated the mall in a panic can use the Kaiser Hospital parking lot as a reunification point to meet up with others in their group.