Walmart store and warehouse workers began walking off the job Wednesday, in California and Washington state, to protest the company's efforts to silence workers seeking better pay and benefits, a workers group said.

Protests will hit 1,000 Walmart stores leading up to and on Black Friday, November 23, the Organization United for Respect at Walmart (OUR Walmart) said in a statement yesterday.

The campaign will hit cities from Chicago and Los Angeles to Dallas and Miami, and include rallies, flash mobs and online actions "to inform customers about the illegal actions that Walmart has been taking against its employees."

It was not clear how many people would take part in the labor action; Walmart's workers do not belong to unions and the company has long been an opponent of allowing them to do so.

The labor action comes after Wal-Mart Stores announced last week it would move up its Black Friday sales to Thursday, Thanksgiving Day, one of Americans' most cherished and family-focused holidays.

Special in-store discount events will start at 8:00 pm (0100 GMT Friday) on November 22, while "customers can get a jump start on shopping" starting early on Thanksgiving Day, Walmart said.

Last year the discount chain opened for the first time at 10:00 pm on Thanksgiving, along with other retailers that pushed the annual sales frenzy earlier to get a jump on the competition.

Black Friday, the day after Thanksgiving, is the traditional kickoff to the year-end holiday shopping season and is considered crucial for retailers' annual earnings. Walmart worker Charlene Fletcher said she was dismayed to find out both she and her husband Greg, also a Walmart employee, were scheduled to work on Thanksgiving instead of being home with their two young children.

"It's heartbreaking to miss the holiday with them, and it's just one more way that Walmart is showing its disregard for our families," Fletcher, an OUR Walmart leader from Duarte, California, said in the statement.

"But when our co-workers speak out about problems like these, Walmart turns their schedules upside down, cuts their hours and even fires people.