The European Union on Wednesday weighed how best to respond to an attempted drone attack at a German airport blamed on Russia but struggled to find new ways to meet the challenge without resorting to military means.

The German government said Tuesday that Russia was responsible for the failed attack at Leipzig/Halle Airport on Aug. 4 using a drone laden with explosives and announced it would shut down a Russian consulate among other measures.

The nature of the incident and its attribution to Russia set a new benchmark. The drone was found near a Ukrainian cargo plane and the device was defused. The airport is a major international freight hub used for providing support to Ukraine.

“It is clear that it has all the hallmarks of state sponsored terrorism. The question is: what do we do about this,” EU foreign policy chief Kaja Kallas told reporters before chairing a meeting of the bloc’s foreign ministers in Ireland.

French Foreign Minister Jean-Noël Barrot said France summoned Russia’s envoy to “protest strongly” and wants to impose sanctions on more of the Kremlin’s shadow fleet ships.