BERLIN

Multiple schools in the northwestern German city of Duisburg shifted to online learning Monday after receiving threatening emails from far-right groups, regional public broadcaster WDR reported.

Police said more than a dozen schools received threatening emails from far-right extremists since Friday, prompting authorities to take precautionary measures while the investigation continues. Police will maintain a presence at several schools on Monday, according to a statement.

“After evaluating the overall situation, experts from Duisburg's State Security came to the assessment that these threats were not serious,” authorities said, although they added that precautionary measures would remain in place “to minimize any potential risks.”

More than a dozen schools suspended in-person classes and switched to online learning on Monday. Several other schools also offered remote learning as a precautionary measure, allowing parents to decide whether their children would attend in person.