Workers at Amazon's San Bernardino air hub in Southern California walked off the job Monday in protest for better wages and working conditions.

Why it matters: More than 150 people participated in the walkout as part of the first coordinated labor action in Amazon’s growing air cargo network, according to the Washington Post.

Yes, but: Amazon contested the figure. Spokesperson Paul Flaningan told WashPost some 74 employees participated in Monday's action.

Driving the news: The workers, who are independently organized, are demanding a $5 an hour pay increase, improved health and safety standards and an end to what they described as "retaliation at the warehouse," according to a statement from Inland Empire Amazon Workers United.

• The group leading the local movement says Amazon is the largest private sector employer in the Inland Empire and alleges that the company failed to provide the community with quality jobs amid massive profits since the start of the pandemic.

What they're saying: "Whether we’re suffering from heat exhaustion, not getting paid enough to afford rent, or being retaliated against for speaking up, we know we deserve better," Inland Empire Amazon Workers United said.

• "We’re demanding higher standards."

The other side: "We appreciate and respect the direct relationship we have with our employees to discuss and address feedback," Flaningan said to WashPost.

• "Through this open-door policy we have many communication channels we use, including All Hands meetings, which help us address employee concerns."

By the numbers: The Amazon Air Freight Fulfillment Center, which opened last year, has about 1,500 employees.

• It's the company's seventh air site in California and uses Amazon Prime-branded airplanes to send packages around the country.

The big picture: Amazon has been pushing back against unionization efforts in its U.S. operations.

• Monday's walkout underscores that a growing labor movement within the company is showing no signs of slowing down.
• Representatives for Amazon did not immediately respond to Axios' request for comment.

Go deeper: Amazon workers' union victory is turbocharging a new labor movement