The facilities join three other Amazon workforces in Illinois and New York City.

Teamsters unions at five additional Amazon facilities have voted to go on strikes, following similar action in New York City and Illinois. The international Brotherhood of Teamsters (IBT) announced in a statement that union members "unanimously" approved measures to authorize strikes in four Southern California facilities and a fifth facility in Atlanta.

The four Southern California facilities are based in City of Industry, Palmdale, Victorville and San Bernardino, according to . This brings the total number of Amazon facilities that have authorized worker strikes to eight. The total includes a facility in Skokie, Illinois and on Staten Island and in Queens. The IBT represents just under 10,000 workers in 10 Amazon facilities nationwide.

These facilities approved a strike right in the middle of the holiday shopping season, one of the busiest and most lucrative times of the year for the online retail giant. Amazon crews went on strike to protest against low wages, hazardous working conditions and "Amazon's illegal refusal to recognize their union," according to IBT statements.

Teamsters General President Sean N. O'Brien said in the statement that Amazon has failed to provide adequate compensation and protections for its workforce. If their demands are ignored, O'Brien says they will start strikes.

"Amazon workers want to earn a good living, have decent health care and be safe on the job," O'Brien said. "They are done with the disrespect and if Amazon keeps pushing them, they will push them to strike."