The Teamsters union continued its nationwide strike against Amazon on Friday, with workers demanding “fair treatment” from the e-commerce giant.

“The Amazon Teamsters movement grows bigger and stronger every day and will not be stopped,” the International Brotherhood of Teamsters said in a statement shared on social media late Thursday, as the strike entered its second day.

The union reported that thousands of workers across key Amazon facilities in New York City, Atlanta, Southern California, San Francisco, and Illinois walked off the job early Thursday. However, specific participation numbers were not disclosed.

Teamsters President Sean M. O’Brien is expected to join the picket line in California’s City of Industry on Friday, underscoring the union’s commitment to the strike during the critical holiday shopping season.

Despite the strike, Amazon has maintained that its operations remain unaffected. Kelly Nantel, Amazon’s director of Global Corporate Issues and Media Relations, claimed the strikes had not impacted deliveries and suggested that many participants were external organizers.

“Thankfully, the vast majority of our employees and the drivers who deliver on our behalf came to work today to do what they do every day,” Nantel said on Thursday. “They’re doing a great job of working for their customers and their communities, and as a result of their hard work.”

The strike comes during Amazon’s busiest season, less than a week before Christmas. The Teamsters have referred to the walkout as “the largest strike in history,” aiming to amplify their push for better treatment and working conditions at one of the world’s largest retailers.