The Teamsters said today its strikes against unfair labor practices were expanding, with Amazon.com workers across several U.S. states joining the union in actions against the e-commerce giant.

The extended strikes in the states of Georgia, California, Kentucky and New York come after 100 Amazon drivers started a strike at the e-commerce giant’s facility in Skokie, Illinois, in June.

As unionization efforts at the online retailer and tech giant picked up, Amazon Labor Union members voted to affiliate with the International Brotherhood of Teamsters that month.

The Teamsters see an opportunity to organize Amazon’s vast workforce and bring their collective bargaining power to bear on the company to reshape labor relations in the e-commerce sector.

Amazon.com did not immediately respond to a Reuters request for comment, while Teamsters did not reply to a question on the number of workers involved in the strikes.

Teamsters, which created an internal Amazon division in 2021, was also instrumental in helping U.S. workers at United Parcel Service secure more favorable contracts last year.

The union is known for its historic battles for workers’ rights in the United States in industries such as trucking and logistics.