Chilling emails were sent to a number of schools in Leipzig, Saxony and Saxony-Anhalt just before 9am local time.
Teachers ordered horrified students at New Nikolaischule Leipzig, a grammar school in the district of Stötteritz, to barricade themselves in after receiving a threatening email.
While Kant-Grammar school in the southern suburbs and the Reclam-Gymnasium were also threatened.
Police stormed two schools in Magdeburg to investigate.
Pupils at the Hegel-Grammar school were sent home, while lessons at the Editha-Grammar continued.
The content of the emails are not yet known.
A police spokesman, Uwe Voigt confirmed that the schools had been threatened.
Anke Hamker, from police Osnabrück confirmed they would be invesitgating the threat.
Worried parents took to social media, with one terrified mother tweeting:”My baby. ;( Just spoke to police. Children are locked in class rooms. Police at the scene. Not someone from school/threat external.”
Germany is on high terror alert after a wave of terror in Angela Merkel”s state over the summer.
More to follow…