Counting is underway in what could be a landmark vote for the US labor movement. Workers have been deciding whether to form the first-ever union at an Amazon warehouse in the country.
Some staff at the plant in the state of Alabama have been demanding better working conditions from the tech giant. They want more pay and longer breaks.
About 5,800 workers at the warehouse voted by post from February to March.
Amazon's management posted website messages calling on employees to vote against unionization.
Local media report the company may dispute the results of the vote. Amazon is one of the biggest employers in the United States.