Thousands of Amazon workers have ended their days-long strike against the company, according to the Teamsters union. But tensions persist, with the union saying its efforts aren’t over.

Amazon delivery drivers and Starbucks baristas are on strike in a handful of U.S. cities as they seek to exert pressure on the two major companies to recognize them as unionized employees or to meet demands for an inaugural labor contract.

Amazon facilities will begin a strike Thursday morning in the final days of the Christmas shopping season. The labor strike represents an attempt by the International Brotherhood of Teamsters to put pressure on the online shopping retailer by threatening to delay some of Amazon's package deliveries during one of its busiest times of the year.