Fake news has been spreading on Twitter ahead of France’s presidential election, according to a new study from Oxford University, though French users are generally sharing more high-quality information than Americans did ahead of the US election. The study’s findings, together with a separate report released earlier this week, come amid concerns that Russia may be seeking to meddle in upcoming European elections as it did in the US last year.

The study from the Oxford Internet Institute (OII), as first reported by Reuters, found that “junk news” reports accounted for 25 percent of all political links shared on Twitter in France, based on an analysis of more than 840,000 tweets posted during a week in March. The study defined junk news as reports that are false and which present “ideologically extreme, hyper-partisan or conspiratorial” viewpoints as facts. Most shared news stories concerned the centrist candidate Emmanuel Macron, who has led some opinion polls ahead of the first round of voting this Sunday, though the OII study says that “highly automated accounts” have at times spread stories about socialist candidate Benoît Hamon, as well.

A separate study published Wednesday by the social media consultancy Bakamo found similar results. Based on an analysis of nearly 8 million political links shared over the course of five months in France, Bakamo found that one in four links were from “sources that help promote ‘fake news,’” including those that spread Russian propaganda and racist views.

Officials in Europe and the US have warned that Russia is seeking to use disinformation to meddle in upcoming French and German elections, as it did during the 2016 US presidential campaign. Macron’s campaign said earlier this year that it has been targeted by Russian-fueled fake news, while the Kremlin has denied any involvement. “I think it’s safe by everybody’s judgment that the Russians are actively involved in the French elections,” Republican Senator Richard Burr, who is also the chairman of the Senate Intelligence Committee, recently said.

Internet companies have taken steps to filter out false or misleading news stories ahead of European elections. Facebook recently launched its fake news filter in France and Germany, and it announced last week that it had suspended 30,000 “fake accounts” in France, in a crackdown against “spam, misinformation, or other deceptive content.”

Yet the Oxford study notes that the spread of fake news has not been as severe in France or Germany as it was in the US. "All in all, US voters were sharing very poor quality news and information about major public policy debates at a critical time before a national election," OII director Philip Howard tells Reuters. "Both German and French voters are sharing much smaller amounts of junk news."

Other research has suggested that most disinformation campaigns have been in support of conservative François Fillon or far-right leader Marine Le Pen, both of whom are seen as Russia-friendly candidates. Nicolas Vanderbiest, a researcher at the Université Catholique de Louvain, recently found that supporters of Le Pen and Fillon were most active in spreading false political stories and rumors on Twitter, as detailed in a report published this week.