The alarm has sounded in Germany. German air base, located next to its airport cologne, was sealed today Wednesday as authorities investigate a possible criminal offense related to the water supply system (bottom photo) which is suspected to have been sabotaged, reports the German Agency and Reuters, which cites a source in the security forces.

The incident was first reported by news magazine Der Spiegel, according to DPA.

According to Spiegel, the water of this base’s water supply network with 4,300 military and 1,200 civilian personnel may be infected after someone breached its perimeter. The magazine adds that the case is being investigated by the police, the military police and the military intelligence service MAD.

Military personnel are not allowed to consume potable water because it may be contaminated.

As reported by the German Agency, a hole was discovered in a fence of the base, which borders the airport, and suspicions were raised of sabotage of the base’s water supply system, although this has not yet been confirmed. Water samples have been taken and are being tested.

Currently not allowed no one to enter or exit from the base and the police have cordoned off the wider area, according to DPA information. The base is home to the fleet of military aircraft used for the travel of the chancellor and his ministers.

Reuters notes that the defense ministry in Berlin and the military intelligence agency MAD were not immediately available for comment. Cologne police said they could not comment.