While Russia’s attempts to influence the 2016 U.S. presidential election have remained in the headlines for months, new reports show the nation also launched destabilizing efforts on social media in Britain ahead of last year’s Brexit vote, according to a report from the Times.

More than 150,000 accounts based in Russia were discovered to have posted Brexit-related content in advance of the referendum in June 2016, according to researchers at Swansea University and the University of California, Berkeley.

According to the researchers, the Russia-run accounts bombarded social media with posts and tweets during a 48 hour period in advance of and during the Brexit vote. The thousands of accounts linked to Russian trolls posted more than 45,000 messages about Brexit, in what is believed to have been a coordinated attempt to manufacture discord among citizens casting a vote about the controversial measure.

The accounts remained primarily dormant prior to Brexit, tweeting fewer than 1,000 tweets per day between all 150,000 accounts before the vote. The accounts increased activity as the day of the referendum drew closer, posting as many as 39,000 tweets in the days just before the Brexit vote.

The accounts—which were found to primarily post content promoting Russian President Vladimir Putin prior to turning their attention to Brexit—mostly posted content that favored voting for Brexit, which would lead to the United Kingdom withdrawing from the European Union.

According to researchers, the accounts reached their peak in activity during the day of voting and continued to post pro-Brexit propaganda until the result of the vote was announced. After it was announced that the measure to withdraw from the EU passed, the accounts almost immediately went silent on the topic.

Tho Pam, the co-author of a paper documenting the behavior of the Russian-controlled social media accounts, told the Times, “the main conclusion is that bots were used on purpose and had influence.”

The findings of the papers echo a similar report published by researchers from the University of Edinburgh who identified a number of Twitter accounts operated by Russian propaganda organization the Internet Research Agency (IRA) that tweeted about Brexit.

The researchers identified 419 accounts that made comments about Brexit. Those accounts were among a group of 2,752 the were suspended by Twitter for their role in spreading propaganda during the 2016 U.S. presidential election.

The accounts were also found to have attempted to sow discord online following a terrorist attack at Westminster Bridge in London earlier this year. The accounts were discovered to have tweeted anti-Muslim rhetoric and some of the more offensive tweets were picked up by local media.

Twitter, Facebook and Google were already facing scrutiny over the role their platforms played in allowing Russia-backed accounts to spread disinformation and create social and political animosity in the U.S. The newly discovered activity of Russian trolls—in some cases from the same accounts that would go on to post about U.S. politics—attempting to influence the Brexit vote is likely to put the companies under an increasing pressure to take action against foreign influence campaigns.