(BSS/AFP) - Romania is holding a suspected "low-level agent" accused of preparing attacks, following the discovery of handguns and ammunition in a forest near Berlin, Germany`s interior minister said Friday.

A Romanian police source told AFP that the suspect in the German case was one of two Ukrainian men in their 20s arrested last October, accused of plotting a parcel bomb attack on behalf of Russia.

Since Moscow`s full-scale invasion of Ukraine in 2022, NATO members Germany and Romania have both reported an increase in suspected Russian espionage and sabotage operations, as well as alleged attack plots.

While he avoided naming Moscow, German Interior Minister Alexander Dobrindt said involvement of a "foreign power" could not be ruled out in the weapons case, adding that federal prosecutors were investigating.

He said it was another "hybrid threat" to emerge in Germany, a term that Berlin uses to describe hostile acts of aggression short of unambiguous military attacks.

After a tipoff, intelligence services and police found two handguns and ammunition stashed in a hideout in the forest, Dobrindt said.

The weapons were rendered inoperable and the site was monitored to see if anyone would collect them, but no one did.

Subsequent investigations, which involved countries in Europe and elsewhere, led to the arrest of the suspect in Romania, who is being investigated by German prosecutors for allegedly preparing attacks and suspected espionage.

German authorities assume the weapons were linked to an attack plan, said Dobrindt, but gave no details about what might have been the target.

"These weapons that were found, including the ammunition, were certainly intended to be used to carry out attack plans," he said.

The suspect, a "low-level agent," was also under investigation in Romania, Dobrindt added.

- `Disposable agents` -

German authorities have accused Russia of recruiting "low-level" or "disposable" agents, often people who are paid small sums of money and have little training, to carry out sabotage, espionage and attacks.

While German officials did not disclose the suspect`s nationality, the Romanian police source, speaking on condition of anonymity, said it was one of the two young Ukrainians arrested in October.

The pair had come to Bucharest from Poland and "handed over to the offices of an international courier company two parcels containing homemade devices, with the intention of destroying the building in question by setting it on fire," according to a police press release at the time.

However, the devices were defused and the Romanian Intelligence Service said it had "foiled a new sabotage operation orchestrated by the Russian Federation on Romanian territory ".

The two Ukrainians were linked to "an extensive network of saboteurs targeting European countries, controlled by the Russian secret services," the Romanian spy service said.

Greens MP Konstantin von Notz, vice-chairman of Germany`s intelligence oversight committee, singled out Russia over the weapons case.

"The latest discovery is yet another indication of how Russia has long been acting with hostility towards us -- and how urgently decisive responses are needed," he told the Rheinische Post daily.

"For many months now, espionage, sabotage and extremely far-reaching attempts to exert influence have been part of everyday life."

The weapons discovery is the latest in a series of security incidents in Germany.

An explosive-laden drone was found this month at Leipzig airport, a key logistics hub for weapons sent to Ukraine, and police deployed a bomb-disposal robot to remove the detonator.

Germany`s domestic intelligence agency has warned for some time that Russia could carry out attacks on defence industry executives, opposition figures in exile, and supporters of Ukraine.

Alleged assassination plots are said to have targeted Armin Papperger, CEO of defence giant Rheinmetall, as well as Stefan Thumann, head of drone maker Donaustahl.