Twitter has hidden a tweet from President Donald Trump about voting, hours before election day.

Mr Trump tweeted that a Supreme Court decision to allow more time for postal ballots to arrive in Pennsylvania was “very dangerous”.

He once again made the widely debunked claim that “rampant and unchecked cheating” would follow.

Facebook also labelled the message with a fact-check that contradicted the president.

The tweet was hidden behind a warning on the president’s account that the content was “disputed and might be misleading”. Twitter has taken similar action against Mr Trump’s account in the past.

Mr Trump also claimed that the court decision would “induce violence in the streets” and that “something must be done!”

On Facebook, the social network did not hide the post, but added the warning: “Both voting by mail and voting in person have a long history of trustworthiness in the US. Voter fraud is extremely rare across voting methods.”

His rival Joe Biden spent the final hours before polling day urging people to make sure they voted, as well as making explicit and direct attacks on President Trump’s record in office.

Vast numbers of Americans have already voted and many have done so by postal ballot, known as mail-in voting in the US.

Controversy around postal delays has led to concerns that not all ballots would reach counting centres in time.

The US Supreme Court ruled that the deadlines for receiving mail-in ballots could be extended by a few days, as long as the votes were postmarked by election day, showing that they had been in transit since.

Mr Trump has repeatedly condemned mail-in voting as unsecured and prone to massive voter fraud. But that is not supported by precedent, and voter fraud has historically been very rare.

Republicans have filed a number of legal cases against alternative types of voting in some states