No explosives found at Zaanstad prison.

A suspicious object was found at the Zaanstad prison on Tuesday. Police are investigating the object. The Explosive Ordnance Disposal unit was called to the scene.
The DJI reported the discovery of a suspicious package on the prison's parking lot. Police immediately responded to the report and secured the area. Investigators found that the package was not an explosive. The Explosive Ordnance Disposal unit examined the object. This event happened after a previous threat at the prison.
Summarized from the sources above. Read the originals for the full story.
Highlights
Suspicious Object Found
A suspicious object was found on the Zaanstad prison parking lot.
Police Investigating
Police are investigating the incident and have secured the area.
No Explosives Detected
The package did not contain any explosives.
EOD Called to Scene
The Explosive Ordnance Disposal unit was called to the scene.
Previous Threat Reported
The incident followed a previous threat at the prison complex.