LONDON — Social media platforms are continuing to crackdown on fringe groups and conspiracy theories following last week's deadly riot at the U.S. Capitol. 

Twitter suspended more than 70,000 accounts associated with the far right QAnon conspiracy and Facebook is removing posts and content fraudulently claiming that the U.S. election was stolen as social media companies scramble to rein in harmful activity ahead of the presidential inauguration on Jan. 20. 

Twitter said Tuesday that given the events last week in Washington, D.C., where a mob of pro-Trump loyalists tried to violently storm the Capitol building, it was taking action against online behavior "that has the potential to lead to offline harm."

In many cases, a single individual operated numerous accounts, driving up the total number of affected accounts, the company said in a blog post. 

"These accounts were engaged in sharing harmful QAnon-associated content at scale and were primarily dedicated to the propagation of this conspiracy theory across the service," the company said.

Twitter's sweeping purge of QAnon accounts, which began Friday, is part of a crackdown that also includes its decision to ban President Donald Trump from the service over worries about further incitement to violence. 

The suspensions mean some Twitter users will lose followers, in some cases by the thousands, the company said.

The QAnon conspiracy theory is centered on the baseless belief that Trump is waging a secret campaign against "deep state" enemies and a child sex trafficking ring run by satanic pedophiles and cannibals. Twitter has been trying to rein in QAnon for months, removing more than 7,000 accounts in July.

Twitter said it's also stepping up enforcement measures and starting Tuesday it will limit the spread of posts that violate its civic integrity policy by preventing anyone from replying to, liking or retweeting them. The policy prohibits attempts to manipulate elections and spread misleading info about their results, with repeated violations resulting in permanent suspension. 

Facebook said late Monday that it will begin removing from its Facebook and Instagram platforms any content containing the phrase "stop the steal." Trump and his supporters have deployed the phrase to push false claims of voting fraud. 

Facebook said that it is still allowing "robust conversations" about the election's outcome. "But with continued attempts to organize events against the outcome of the US presidential election that can lead to violence, and use of the term by those involved in Wednesday's violence in DC, we're taking this additional step in the lead up to the inauguration," executives said in a blog post. 

The company said it may take some time to "scale up" the new enforcement measure but it has already removed a "significant number of posts," without giving a specific number.