Hamburg police on November 8 said they had arrested four children and seized a pair of "apparent toy weapons" after a major operation at a school in the Blankenese district of Hamburg.

Students were evacuated from the premises following reports that two young people at the school had threatened to use a gun.

Police spokesperson Holger Vehren told reporters that special forces completed a search of the building and found no trace of the perpetrators.

But later on November 8, police said they were called to another "threat," not far from the school, that resulted in the arrest of four children — two 12-year-olds, a 13-year-old and a 14-year-old.

"It later emerged that one of the 12-year-olds and the 13-year-old could also be responsible for the crime" at the school, said police, adding that officers also "seized two apparent toy weapons."

What do we know about the incident?

Tactical forces were deployed to the school in the Blankenese district shortly before 11 a.m. local time after "indications of a threat situation," police said.

The German mass-circulation daily newspaper Bild had reported that two young people, possibly students, had barricaded themselves into a classroom with one of them threatening that they would use a gun. A female teacher was said to have been threatened.

The school was evacuated, and parents were asked to head to a nearby barracks where the pupils were taken.

Streets surrounding the school were cordoned off with police helicopters circling above the school as officers looked for the two perpetrators.

Police spokesperson Vehren said the teacher "who was specifically threatened" and students of the eighth-grade class would be questioned as part of a criminal investigation.

Blankenese lies on the Elbe River and is considered one of Hamburg's most wealthy districts. The Blankenese district school has some 1,150 students.