The study, authored by PhD candidates at the University of Warwick, has been available in draft form since early this year. It was updated on Tuesday and highlighted by The New York Times in a report focusing on Facebook’s influence in Altena, a German town with above-average levels of anti-refugee violence.

The study examined more than 3,000 anti-refugee incidents in Germany between 2015 and 2017, including arsons and assaults. It analyzed the communities around the attacks, measuring variables such as income levels, size, and concentration of refugees. It found that, after controlling for such variables, higher-than-average Facebook use consistently and strongly corresponded with higher levels of anti-refugee violence.

Some of the study’s individual findings document correlations without necessarily implying that Facebook usage causes hate crimes. In a portion of their analysis tracking anti-refugee content shared on the social network to violent incidents, for instance, the authors write that their findings could reflect Facebook users reacting to violence, rather than the other way around.

But the study used other approaches to pin down Facebook’s role as a driver of violence. The researchers found that localized severe disruptions in internet access—cutting residents of a locality off from Facebook—eliminated the correlation between Facebook use and hate crimes.

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The Times report on Altena fleshes out those findings. In one incident shared by the manager of a refugee integration center there, a Facebook page set up to solicit food donation for Afghan and Syrian refugees was deluged with angry, anti-refugee rhetoric. That’s despite what the Times describes as “overwhelmingly tolerant social norms” in the town, suggesting that Facebook serves to concentrate and amplify attitudes that, without it, would remain marginalized.

The most extreme and persistent voices on a platform like Facebook, meanwhile, have outsized influence. The resulting sense that hateful attitudes are more widespread than they may actually be, in turn, encourages actual violence. In Altena, a trainee firefighter was radicalized online and attempted to burn down refugee housing.

The issue is particularly salient in Germany, where treatment of refugees from Middle Eastern conflicts has created growing political rifts. As the study points out, Germany’s far-right, anti-immigration party, Alternative for Germany (AfD), has more Facebook followers than any other German political party. In addition, the study found strong correlations between anti-refugee posts to AfD’s Facebook page and anti-refugee incidents in the real world.

Facebook has also been implicated in waves of ethnic violence in Myanmar and Sri Lanka. The company has often seemed slow to respond to requests from local governments to rein in users propagating hateful ideas, including misleading or false claims about crimes committed by members of marginalized groups. Facebook has, however, recently stepped up efforts to remove hate speech on the platform.

Facebook declined to comment on the new study to the Times and has not yet responded to Fortune’s request for comment.