The German Defense Ministry said an investigation had found no evidence that the water supply at a large Luftwaffe barracks in West Germany had been tampered with. Two days earlier, the facility had been sealed off for hours for fear of possible acts of sabotage.

BERLIN — An investigation has found no evidence that the water supply at a large Luftwaffe barracks in West Germany had been tampered with, the Defense Ministry said on Friday, two days after the facility was sealed off for hours for fear of possible acts of sabotage.

The investigation was launched on Wednesday after a hole was discovered in a fence near the waterworks at the Wahn barracks outside Cologne and what the military called “abnormal water levels” were reported. The facility was cordoned off in case one or more perpetrators were on site, but no one was found and the gates were reopened.

The Ministry of Defense wrote on the social network X on Friday that “manipulation of the drinking water system could not be confirmed after extensive investigations” and that the quality requirements for drinking water were met. It added that “further investigations are underway” without giving details.

The Wahn Barracks serves the military part of Cologne/Bonn Airport, where the German government’s fleet of military aircraft has its main base.

The incident occurred at a time of nervousness about the potential vulnerability of the infrastructure to Russian sabotage attempts.

In the barracks town of Mechernich in the west of the country, officials announced on Thursday evening that they had discovered a hole in a fence on the site of a drinking water tank. They called on 10,000 residents not to use the water.

On Friday, they said an analysis had found no signs of chemical or biological contamination and recommended that locals boil the water before drinking it as a precaution while further tests were carried out.