Facebook pledged to fight misinformation about climate change. Then it suspended a slew of environmentalist groups.

• The Facebook accounts of several environmentalist groups were suspended this week, leaving them unable to post on Facebook or send messages through the platform.
• Groups that focus on climate justice including Greenpeace USA, Climate Hawks Vote, and Rainforest Action Network said they were suspended without warning.
• The suspensions came a week after Facebook vowed to crack down on misinformation that denies the existence of climate change and rolled out a "climate science information center" to inform users about global warming.
• Facebook said the groups were suspended by mistake and that they have since been restored.

Last week, Facebook announced a raft of new policies meant to spread awareness of climate change and fight misinformation that denies the existence of global warming.

This week, several high-profile environmentalist groups said their Facebook pages were suspended without warning.

Climate activist groups including Greenpeace USA, Rainforest Action Network, and Climate Hawks Vote were locked out of their Facebook pages over the weekend, unable to post updates or send messages. The activist groups also said hundreds of individuals' Facebook accounts linked to the groups were suspended, The Guardian first reported.

Activists noted that the suspended organizations were all planning a day of online action to protest KKR & Co, an investment firm financing the construction of a new natural gas pipeline in Canada. Many were suspended and unable to promote the event in time.

In the days that followed, most of the Facebook accounts were restored, but activist groups said Facebook didn't issue an explanation for their suspension.

Facebook spokesperson Daniel Roberts said in a statement to Business Insider that the groups were mistakenly suspended but have since been reactivated.

"Our systems mistakenly removed these accounts and content. They have since been restored and we've lifted any limits imposed on identified profiles," Roberts said.

Climate activists have previously pressured Facebook to take more action to combat misinformation and climate change denial. While Facebook's third-party fact checkers are meant to debunk posts that falsely claim global warming doesn't exist, Facebook's policies exempt opinion articles from being fact-checked. One group that claims carbon emissions are good for the environment evaded a fact-check because its post was labeled as opinion by Facebook.