The offending posts both shared a link to a video in which Trump claimed that children are "almost immune" to the coronavirus, Reuters reported. Facebook said it was the first time it had removed a post by the president for sharing coronavirus misinformation.

"This video includes false claims that a group of people is immune from COVID-19 which is a violation of our policies around harmful COVID misinformation," Facebook spokesperson Andy Stone told NPR of the social media giant's decision.

Facebook removed the post from the President's own page, while Twitter removed a post of the video shared from the Trump campaign account @TeamTrump.

"The @TeamTrump Tweet you referenced is in violation of the Twitter Rules on COVID-19 misinformation. The account owner will be required to remove the Tweet before they can Tweet again," Twitter spokesperson Trenton Kennedy told NPR.

The campaign complied and is now tweeting again.

The video contained a clip from a Fox News interview Trump gave Wednesday morning, in which he argued for schools to reopen.

"If you look at children, children are almost — and I would almost say definitely — but almost immune from this disease," Trump told "Fox & Friends," according to a CNN fact check of the interview. "They don't have a problem. They just don't have a problem."

But CNN's Daniel Dale explained why that wasn't true.

"While children are, on the whole, less likely to get seriously ill or die from the coronavirus than adults are, they are certainly not 'immune,'" he wrote. "Children get infected, transmit the virus, and do sometimes get seriously ill or die."

The World Health Organization found that children aged five to 14 years old made up 4.6 percent of 6 million infections between Feb. 24 and July 12, according to Reuters. A large study out of South Korea last month found that younger children were less likely to spread the virus than adults, but children aged 10 to 19 could spread it just as much, The New York Times reported.

White House deputy national press secretary Courtney Parella defended Trump's statement in the removed video.

"The president was stating a fact that children are less susceptible to the coronavirus. Another day, another display of Silicon Valley's flagrant bias against this president, where the rules are only enforced in one direction," she said in The New York Times. "Social media companies are not the arbiters of truth."

However, CNN's Oliver Darcy argued that Trump's statement in the Fox interview went much further than Parella's summary. At one point in the interview, Trump said it was a fact that children were "virtually immune" from the disease, and Facebook confirmed to Darcy that this quote was featured in the removed video.

Darcy further criticized Fox News for allowing Trump's claims to air unchallenged in the first place:

What is noteworthy is that the action means that — on this issue — the two tech giants have enforced higher standards on their platforms than the Murdoch family has enforced on Fox News. Whereas Twitter and Facebook removed the clip, the hosts of "Fox & Friends" didn't challenge Trump when he made the false claim on the network's air. And, Fox News — which didn't provide me a comment — played Trump's remarks to its large audience later in the day without a fact-check.

The video was on Facebook for around four hours and seen almost half a million times before it was removed, The New York Times reported.