Dozens of Black Friday shoppers were involved in a brawl at a Walmart in Palmdale, California, according to police.

The incident occurred inside the mega chain store at approximately 6:30 p.m. local time and involved two groups of roughly a dozen people each. Details surrounding the cause of the fight are presently unknown, the Los Angeles County Sheriff’s Department told reporters. Investigators are working to determine whether a store item sparked the brawl or a separate matter.

Further detailing regarding the event, including the suspects’ identities, are also unknown at this hour.