German security authorities uncovered a cache of handguns in a forest near Berlin last year, believed to have been intended for assassinations carried out on behalf of Russian intelligence. The discovery was reported jointly by the daily Süddeutsche Zeitung and the public broadcasters NDR and WDR on Friday, citing unspecified sources.

The reports said one suspect had been arrested in Romania and may have been responsible for setting up the weapons storage. Germany's Interior Minister Alexander Dobrindt told a press conference that authorities were in touch with their Romanian counterparts over the potential extradition of the suspect. "This case demonstrates that we are operating under a high threat level," Dobrindt said.

The federal public prosecutor's office was investigating the case on suspicion of planning a serious act of violence posing a threat to the state, the report said. Germany's domestic intelligence service, which has been warning of a heightened risk of Russian sabotage or assassination attempts, was convinced that those setting up the cache were acting on orders from Russian services. The report also said potential targets included defence industry executives, exiled opposition figures, and supporters of Ukraine.

The Russian embassy did not immediately respond to a request for comment. The federal public prosecutor and the domestic intelligence service declined to comment.

The Guardian, reporting on the same story, said the weapons were believed to be used to carry out assassinations on behalf of Russian intelligence. It noted that the report by Süddeutsche Zeitung, NDR, and WDR had cited unspecified sources, and overall it described that the federal public prosecutor's office was investigating on suspicion of planning a serious act of violence posing a threat to the state.

The German authorities have not officially confirmed or denied the details of the reported plot beyond the interior minister's acknowledgment of the case. The arrest in Romania was confirmed by the German side as well.

No further details have been released about the suspects or the specific targets, and the investigation is ongoing.