Germany's top naval officer said "more than one" of its warships were recently sabotaged.A day before, a local report said a corvette-class vessel had metal shavings poured into its engine system.Without expressly accusing any party, the German naval chief warned of a growing threat from Russia.Germany's naval chief said on Tuesday that several of Berlin's warships were sabotaged.Vice Adm. Jan Christian Kaack, the inspector of the German navy, said at a press conference on Tuesday that the damage involved "more than one unit."Kaack also said there had been attempted break-ins at German naval bases via land and sea, and he spoke of "attempts to approach" uniformed personnel while they were heading home.The vice admiral did not give further details on the sabotage attempts or explicitly say who was behind them. But Kaack issued a general warning about Moscow while speaking with reporters."The growing threat from Russia is more urgent at the beginning of 2025 than it was two years ago," he said.Kaack's comments follow a report published on Monday by the local outlet Sddeutsche Zeitung, which said that German police were investigating an incident at a Hamburg shipyard where several dozen kilograms of metal shavings were dumped into a corvette-class vessel's engine system.Per the joint report from broadcasters WDR and NDR, the corvette was a brand-new ship called the "Emden" awaiting delivery to the German military. It's scheduled for deployment to the Baltic Sea, the outlets reported.Sddeutsche Zeitung wrote that if the shavings hadn't been detected during an inspection, they would have caused significant damage to the ship.At Tuesday's press conference, Kaack was asked to address Sddeutsche Zeitung's report, but he did not directly confirm the "Emden" incident when speaking about sabotage.The "Emden" is one of the five new K130 corvettes that Germany ordered for delivery in 2025 to fulfill its NATO requirements.Naval Vessels Lrssen, the company responsible for building the ships in Hamburg, told Agence France-Presse that the "Emden" had recently completed a "successful sea trial."It did not respond to a request for comment sent outside regular business hours by Business Insider.Germany is already on high alert for sabotage attempts after multiple incidents in the last two years that include a package catching fire on a plane and a fire at an ammunition factory in Berlin.More recently, a German ammo factory in Spain was hit by an explosion in late January that injured six workers.German authorities have repeatedly suggested that Russia is the prime suspect, but are still investigating many of these cases.Ukraine's allies have accused Russia of waging a "hybrid war" against the West, with reports of an attempted assassination against a defense contractor CEO and the growing assessment that Russia-linked oil tankers damaged undersea infrastructure cables in the Baltic Sea.The Russian government and the German navy did not respond to requests for comment from BI, sent outside regular business hours.