By msnbc.com wire reports

A shopper who allegedly fired pepper spray at other customers during a Black Friday sale for Xbox video games has surrendered to authorities, Los Angeles police said Saturday.

Police Sgt. Jose Valle told the Associated Press that the woman who allegedly caused minor injuries to 20 shoppers, including children, at a Los Angeles-area Walmart had turned herself in Friday night.

She was released pending further investigation after she refused to discuss the incident, police said Saturday.

The woman's identity was not released. 

The alleged attack took place about 10:20 p.m. Thursday, shortly after doors opened for the sale. Employees brought out a crate of discounted Xbox video game players, and a crowd formed to wait for the unwrapping. Valle said the woman began spraying people in order to get an advantage.

Wal-Mart officials called it "an unfortunate situation."

"We're glad everyone seems to be OK," Wal-Mart said in a statement. The company pledge to assist authorities with the their investigation.

The incident was among those nationwide in which violence marred the traditional kickoff to the holiday shopping season on the Friday after Thursday's Thanksgiving holiday.

Walmart seemed to have a worse day than many other retailers as shoppers screamed, shoved and elbowed each other to save a few bucks.

Incidents across the country included a man shot by robbers in the parking lot outside a San Leandro, Calif., store and shoppers pepper sprayed by security at a store in Kinston, N.C.

A fight for bath towels, purportedly recorded at a Michigan store, has become a YouTube sensation. Cheap towels also caused mayhem at a Walmart in Oregon, Ohio.

"They were fighting over bath towels on sale for $1.88, as ridiculous as that sounds," Police Sergeant Jason Druckenmiller told Reuters. "A woman tried to get her hands on some towels when she was pushed from behind, and that's when she came out swinging."