School administrators at a major Swedish university announced late Sunday afternoon that classes Monday, Oct. 12, would be canceled in light of a menacing online threat.

On the Lund University website, administrators wrote that there was an anonymous “threat on Sunday leveled against the university and its students" and that police deemed it “very serious.”

Swedish news outlet Sydsvenskan reported that the anonymous post referenced the Oct 1. shooting at an Oregon community college, but police have yet to release any official details. “Police have called in extra resources to work with the matter,” Sydsvenskan noted (according to Google Translate). “It is about assessing whether some form of monitoring [should] be deployed and to see if the anonymous” user can be tracked.

According to school administrators, the threats were made through the app Jodel. 

Jodel is a German anonymous messaging platform geared for college students."In real time you'll see recent Jodels (posts) and interact with other users without exposing your personal information,” the app notes on its site. The app is similar to Yik Yak, a Georgia-based anonymous app commonly used by high school and college students.

This is hardly the first time anonymous online threats have led to school shutdowns. In March 2014, for instance, threats made over Yik Yak at a Boston-area high school led to a school evacuation. A few months later, in November 2014, more anonymous threats made over Yik Yak shut down two California high schools in one week.

Lund University is one of the oldest and largest schools in Sweden. Founded in 1666, it has about 42,000 full-time students and an academic staff of 4,300.