Hundreds of Amazon warehouse employees in the US went on strike Tuesday against what they say are unsafe working conditions amid the coronavirus pandemic, organizers said.

"More than 350 workers have now pledged" to strike, the Athena coalition, a group of workers' rights organizations, said in a statement, adding that the stoppage would be effective "starting today."

However, according to Amazon, unions "grossly exaggerated" the level of participation in the protests.

"More than 250,000 people have come to work today, even more than last week to serve their communities," spokeswoman Lisa Levandowski said.

"We encourage anyone to compare the health and safety measures Amazon has taken, and the speed of their implementation, during this crisis with other retailers," she added.

Amazon says unions have "grossly exaggerated" employee participation in strikes
Amazon says unions have "grossly exaggerated" employee participation in strikes AFP / Thomas SAMSON

Two weeks ago, Amazon announced it was distributing millions of masks to employees and implementing temperature checks at all of its US and European sites.

But, according to Athena, the application of these measures has been "questioned repeatedly by workers on the ground."

The online retail giant has been accused since the start of the pandemic of failing to sufficiently protect its employees and of firing employees in the US who led protest movements.

The protest comes just days before a planned online strike by Amazon coders and engineers.

The company has said it will recruit 175,000 new employees in the US to help with runaway demand as people locked down because of the pandemic order things online.