President Trump took to Twitter late Saturday to falsely claim he had won the 2020 presidential election, airing a fresh barrage of baseless attacks mere hours after Democratic candidate Joe Biden had achieved victory.

His post — coming after major media networks said Trump lost the election — prompted Twitter to immediately slap a label on the tweet, saying “This claim about election fraud is disputed.” The tech giant, however, took minimal action to limit Trump’s millions of followers from viewing it or re-sharing it widely.

The president’s all-caps tweet questioned the integrity of the vote, alleging “BAD THINGS” had occurred, even though he has not presented any evidence of electoral fraud.

The tweet threatened to sow online discord on the very day that news organizations called Biden the president-elect because he exceeded 270 electoral votes. Other top Trump allies and surrogates throughout the day similarly sought to undermine confidence in Biden’s apparent victory — and raise money for potential legal challenges in key battleground states.

Trump’s incendiary comments threatened to create new headaches for Twitter, which has sought to clamp down on the spread of provably false content on its platform. As Americans cast their ballots, the tech giant ramped up its enforcement efforts, ultimately labeling or limiting the reach of dozens of problematic tweets by either the president or his allies in recent days. But Twitter’s heightened vigilance has hardly deterred the sitting Republican commander-in-chief, raising questions about how Silicon Valley plans to handle the precarious period between the election and Trump’s departure from office.

On Saturday, the company opted against placing a gray box over Trump’s comment that would have removed it from public view. And it did not impose other restrictions, including on comments and favorites, that might have similarly limited its reach.

“With the election now called by multiple sources per our public guidelines, we will no longer apply warnings on tweets commenting on the election outcome,” Brandon Borrman, a spokesman at Twitter, said in a statement. “We will continue to apply labels to provide additional context on Tweets regarding the integrity of the process and next steps where necessary.”

Trump’s eruption on Saturday marks only the latest in a line of controversial and incorrect attacks that he and his allies have unleashed since Election Day. His aides earlier this week claimed victory in Pennsylvania, a state Trump did not actually win, and the president’s son has shared hoaxes about the vote-counting process that have been widely rebuked.

Trump’s campaign, meanwhile, has fired off millions of emails and text messages seeking to push the incorrect narrative that the election had been stolen — and raise money in part to retire their campaign debts. The campaign’s top digital director, Gary Coby, also runs a text-messaging firm that has been linked to a series of texts sent in Philadelphia that seemed to encourage people to protest the ballot-tabulation process there, the Post first reported.

The deluge of disinformation —— particularly during the high-stakes election — has forced Silicon Valley social media companies to take a more aggressive role in policing political speech after years of resistance. On Facebook, for example, Trump’s earlier posts falsely claiming victory prompted the company to place a large banner that instead indicates that Biden is the projected winner.