A group of fast food workers Thursday protested alleged wage theft outside a McDonald's restaurant in South Los Angeles as part of a nationwide campaign to press for a minimum wage raise.

Protesters claimed that they are victims of wage theft and they have joined elected officials, community allies and faith leaders to protest "systemic and illegal labor abuses in the industry."

The action came as two former McDonald's managers spoke out for the first time about how they were forced to steal from workers' checks. In a video made public Tuesday, the managers talked about how they shaved time off workers' schedules and other practices designed to avoid paying workers for all the hours they worked.

The protest occurred just days after the first-ever national poll of fast food workers in the U.S. found that 89 percent of employees surveyed at companies like McDonald's, Burger King and Wendy's reported having wages stolen from them.

Reports said labor unions have planned to launch similar protests in other U.S. cities as a nationwide campaign to support U.S. President Barack Obama's push for raising minimum wage at the federal level.

Obama said in a speech Wednesday in Michigan that raising the minimum wage would raise millions of people out of poverty.

President Obama wants to raise the federal minimum wage to 10.10 dollars an hour, or about 21,000 dollars a year for full-time workers. The current pay of 7.25 dollars an hour, or 15,000 dollars a year, was raised in 2009. Democrats at the U.S. Congress generally support the raise but Republicans oppose it.

The Hart Research and Associates conducted the nationwide survey for the Low Pay is Not OK campaign by polling more than 1,000 fast food workers. The survey said 84 percent of workers at McDonald's, 92 percent of workers at Burger King, and 82 percent of workers at Wendy's reported that they have experienced some form of wage theft at their jobs.

According to the survey, 60 percent of workers said they have been required to perform tasks before clocking in, or after clocking out, with 46 percent being forced to do so multiple times, and 43 percent have been denied a break during long shifts.

About 48 percent of workers who have worked more than 40 hours in a single week said that they do not always receive the overtime pay they are owed, according to the survey.

Last month, lawsuits were filed in California, Michigan and New York alleging that McDonald's is systematically robbing employees by forcing them to work off the clock, shaving hours off their time cards and not paying them overtime, among other practices. The suits demanded McDonald's, which earned nearly 5.6 billion dollars in profits in 2013, pay back the stolen wages and stop its illegal theft of workers' pay.

McDonald's Corp. said in a statement on its website that it planned to investigate the allegations and take necessary actions.

In 2011, 3.8 million American workers earned the federal minimum wage of 7.25 dollars per hour or less, according to estimates by the U.S. Bureau of Labor Statistics.

A nationwide debate has heated up recently about whether the government should raise the minimum wage, increasing both the earnings of the lowest-level employees and the costs for employers.

Supporters said an employee working a 40-hour week at the federal minimum wage would earn 15,080 dollars per year. This income would leave a two-person household just below the federal poverty threshold of 15,130 dollars.

But opponents claim a higher minimum wage would be a heavy burden on employers, especially small business owners who in turn would be unable to hire as many people.