Celebrities and Twitter users have taken to the social network to call on online retail giant Amazon to pull its advertisements from right-wing Breitbart News.

On Monday, an activist group campaigning against Breitbart said it has pressured nearly 2,600 companies to withdraw their advertisements. The company confirmed the boycott.

The calls come as former White House adviser Steve Bannon, who was let go from the administration last week, has resumed his position as head of the organization.

The website is known for publishing controversial content including conspiracy theories about Hillary Clinton and former President Barack Obama.

Amazon is owned by Jeff Bezos, who also owns the Washington Post.