Polish SIM cards were found inside some of the Russian drones that entered Polish airspace during a mass incursion in September 2025, Polish outlet RMF24 reported, citing findings from a Polish prosecution investigation.

SIM cards can allow drones to connect to local cellular networks for functions such as communications, data transmission, telemetry, or navigation-related services. However, investigators have not said what the Polish SIM cards found in the Russian drones were used for. The details remain classified.

The SIM cards were discovered in some of the Russian Gerbera drones recovered after the incursion, RMF24 reported.

Investigators have not disclosed whether the SIM cards were stolen or obtained illegally.

The investigation into the September 9–10, 2025 incursion was ultimately closed after prosecutors failed to identify those responsible for violating Polish airspace.

More than 30 drones entered Poland

The incursion took place overnight on September 9–10, 2025, during a large Russian missile and drone attack on Ukraine. More than 30 Russian Gerbera drones entered Polish airspace from the east and came down at 27 locations across the country, according to RMF24.

Polish forces intercepted and shot down multiple drones, with the Territorial Defense Forces deployed to search for wreckage and other objects that came down on Polish territory. Poland also maintained contact with NATO command throughout the operation.

The incident prompted Poland to close four airports – Warsaw Chopin, Warsaw-Modlin, Rzeszów-Jasionka and Lublin – because of the military activity. 

Polish officials described the airspace violations as unprecedented and a serious threat to national security. The incident marked the first time since Russia's full-scale invasion of Ukraine that Polish forces had used weapons against Russian aerial objects that entered the country's airspace.

The mass incursion subsequently became the subject of a criminal investigation into the violation of Polish airspace and the threat to public safety.

Investigation closed without identifying perpetrators

After months of investigation, Polish prosecutors closed the case because they were unable to identify the perpetrators, according to Lublin District Prosecutor’s Office spokesman Marcin Kozak, as cited by RMF24.

Most of the case files, including the justification for the decision, are classified.

Prosecutors cleared Poland's military response

Investigators also examined whether the Polish military had responded properly to the drone incursion.

According to RMF24, prosecutors concluded that the military acted in accordance with procedures. Polish troops had the right to use force and shoot down hostile objects, and prosecutors found no irregularities in their response.

The investigation was therefore closed both over the failure to identify the perpetrators and over the assessment of the Polish military's actions.