Germany’s Stuttgart Regional Court of Appeal on Tuesday sentenced a Ukrainian citizen to one year and three months in prison.

Prosecutors described the case as a plot linked to Russian intelligence to blow up postal parcels in Europe.

According to a statement by the court, three Ukrainians were involved in sending two packages containing GPS trackers and car spare parts from Germany to Ukraine through an Ukrainian postal company. The court said the operation was initiated by a Russian state entity whose name was not mentioned.

The case is part of a wave of European concern about sabotage linked to Russia. In July of last year, a package caught fire at Leipzig Airport in Germany before being loaded onto a DHL cargo aircraft; security agencies considered the incident to be possible sabotage linked to Moscow.

Three explosions of suspicious postal parcels suspected to be sabotage occurred in the same period in the UK, Germany and Poland.