Trump supporters claim conspiracy after Reddit 'quarantines' their biggest message board, The_Donald

Users will now be shown a warning sign before being allowed to view pro-Trump forum

A sign hangs on the door of an office at Reddit headquarters in San Francisco, California April 15, 2014 (REUTERS)

Reddit has quarantined the popular pro-Trump subreddit The_Donald - citing threats against law enforcement officers.

The forum is Reddit's most popular section for Donald Trump's supporters, and the president even held an "ask me anything'' session during his 2016 election campaign.

Some users had apparently encouraged violence against law enforcement, angry that officials in Oregon were trying to bring back Republican state senators who left the state to avoid voting on a climate-change bill.

The quarantine status means that anyone who want to access this section now have to acknowledge a warning that the subreddit violated some of Reddit's content rules, and its posts may not appear in a Reddit search.

According to Reddit's rules, a quarantined community ''prevent its content from being accidentally viewed by those who do not knowingly wish to do so, or viewed without appropriate context."

Moderators for the site appeared to allude to a conspiracy, posting on the site: “It would seem they’ve set up an impossible standard as a reason to kill us before the 2020 election.”

The subreddit was created in June 2015, shortly after Donald Trump announced his campaign for the presidency, and has been a central hub for Trump supporters ever since.

Members of the subreddit share memes and ideas, and Brad Parscale, Mr Trump's campaign manager, said in 2016 that he visited the page daily.

The official Twitter account of the subreddit wrote on Wednesday: "They waited until the election to totally suppress us," drawing a link between the Democratic debate and the quarantine.

This is not the first time Reddit has tried to minimise The_Donald's visibility: in 2017, the site changed its setting so posts from The_Donald don't appear on Reddit's front page (although it did the same for the SandersForPresident subreddit). It also cracked down on the subreddit's "most toxic" content in December 2016.