Twelve US state prosecutors demanded Wednesday that Facebook and Twitter take stronger action to stop the spread of false information about Covid-19 vaccines on the social media sites.

In a letter sent to Facebook boss Mark Zuckerberg and Twitter chief Jack Dorsey, the state attorneys demanded that the sites remove accounts belonging to prominent "anti-vaxxers."

"The people and groups spreading falsehoods and misleading Americans about the safety of coronavirus vaccines are threatening the health of our communities, slowing progress in getting our residents protected from the virus, and undermining economic recovery in our states," the prosecutors wrote.

The letter, which was signed by New York Attorney General Letitia James, quotes figures from the Center for Countering Digital Hate which estimates that there are 59 million subscribers to anti-vaccine accounts on Facebook, Instagram, Twitter and YouTube.

The letter adds that digital research groups estimate that 12 accounts are responsible for 65 percent of anti-vaccine content on Facebook, Instagram, and Twitter.

"Anti-vaxxers" are using social media platforms to target Black communities, who are already known to be more skeptical about vaccines because of historical reasons.

The prosecutors criticized Facebook for failing to apply misinformation labels to pages and groups created by anti-vaccine activists.

The appeal came ahead of a highly anticipated hearing in Congress Thursday in which Zuckerberg, Dorsey and Google boss Sundar Pichai will be grilled on disinformation.

Coronavirus