Political groups which create websites designed to look like news outlets will no longer get the same treatment as independent media on Facebook, the social network said Tuesday.

Facebook said the rise of political sites masquerading as news outlets prompted a change in policy, and that  these won't be included as part of its Facebook News.

These partisan sites may remain on the platform but will no longer get a "news exemption" for their ads and will be "held to the same standard as political entities on Facebook," according to a statement from the California giant.

The sites won't have access to news messaging on the Facebook services WhatsApp and Messenger.

"We recognize that there are a growing number of news publications that are connected with different types of political entities and other organizations that can primarily engage in the influence of public policy or elections," Facebook said in a blog post.

"They must adhere to the authorization and disclaimer process for ads about social issues, elections, or politics in the Ad Library."

Researchers have identified more than 1,200 partisan sites designed to appear to be local news but with over 90 percent of their stories algorithmically generated using public data sets or by repurposing stories from outside sources.

Some analysts call these outlets "impostor sites" pretending to be news organizations without the varied and balanced coverage most people expect.

"As we prepare for the election, we are absolutely committed to make sure we are protecting the integrity of those elections," Facebook vice president of integrity Guy Rosen said on a conference call with reporters.

"We are always working with partners to understand new risks and what may go wrong, and ensuring we are preparing for different scenarios that may occur."