BERLIN — German officials say they are investigating whether the deaths of 18 porpoises in the Baltic Sea are connected to a navy demining operation earlier this year.

A spokesman for Germany’s Defense Ministry said Monday that “so far no direct link has been established” between the detonation of 42 WWII-era mines and the deaths of the endangered marine mammals.

Frank Faehnrich told reporters that should a link be found "we obviously regret it."

Stranded whales die again on Hawaiian shores
Stranded whales die again on Hawaiian shores

But this time Navy sonar likely played no role in their deaths.

By: Audrey McAvoy, The Associated Press

The mines were blown up in August during a NATO maneuver, after civilian authorities warned they were becoming increasingly unsafe with age.

Environment Ministry spokesman Stephan Gabriel Haufe said the detonation took place in a marine reserve and that porpoises in the Baltic enjoy “particularly strict protection.”