This article is more than 2 years old.

April 24, 2017 This article is more than 2 years old.

Anti-Semitic violence is on the decline worldwide, but online attacks against Jews may be worse than ever, two new reports say.

In 2016, anti-Semitic violence dropped 12%, according to research from Tel Aviv University’s Kantor Center, from 410 major incidents in in 2015 to 361 last year. The study covers 40 countries spanning several regions, and the violent incidents include attacks with or without weapons, arson, vandalism, and desecration.

Fewer incidents reported in countries with large Jewish populations, such as France, account for the bulk of the decline. The center attributes this to several possible factors, including increased security and surveillance of radical groups. But the numbers may be down because they are up for another group being increasingly targeted amid the refugee crisis in Europe—Muslims.

The researchers also say that “anti-Semitic incidents and manifestations in 2016 reflect two parallel yet contradicting trends.” While violent and non-violent incidents in the physical world has decreased, online hate has become,”more and more threatening, cruel and violent.”

Another report, to be released in full on April 25, quantifies internet anti-Semitism. The World Jewish Congress found that in 2016, 382,000 anti-Semitic posts appeared on social-media platforms, making the average “more than 43.6 posts per hour, or one post every 83 seconds.” The posts did not include those that simply are critical of Israel.

After analyzing millions of posts in 20 languages on various platforms, the organization found that the majority of these hateful messages can be found on Twitter:

Quartz reached out to Twitter for comment, and will update this post with any response.

The authors of the Kantor Center report emphasize that you don’t need physical attacks to create an atmosphere of fear. “Even if the number of violent cases decreased, the prevalent feeling among Jews—individuals as well as communities—is an ominous one, and constitutes the most worrisome finding.”

In the US, the pernicious hate hits a particularly vulnerable community: the research found that US campuses continued to be a ”hotbed for anti-Semitism,” which experienced a 45% increase in anti-Semitism in all forms.

The release of both reports was centered on Yom HaShoah, Israel’s Holocaust Remembrance Day, marked on April 23-24.