Unidentified drones were spotted hovering over a military base in western Germany, housing components for the US-made Patriot air defense systems, days after an explosive device was discovered at Leipzig airport. The Bundeswehr, Germany's armed forces, confirmed the drone sightings on Thursday evening at Mechernich base, near Bonn. The incident has sparked an investigation by military and local police, amidst escalating security concerns across Europe. This latest occurrence comes as European nations offering support to Ukraine in its ongoing conflict with Russia face increased threats. Moscow has consistently denied any involvement in these incidents. German Interior Minister Alexander Dobrindt highlighted the country's vulnerability to "hybrid warfare" attacks, while investigations continue into how a drone laden with explosives reached Leipzig/Halle airport, used by NATO, the German military, and Ukraine's Antonov Airlines. The Bundeswehr remains tight-lipped about the ongoing investigation regarding the suspected origins of the drones over Mechernich. Meanwhile, local police have been contacted for comment, with reports suggesting that the base houses a storage facility for equipment used to maintain Patriot missile batteries. These air defense systems have become crucial in Ukraine's ability to intercept Russian ballistic missiles since Moscow's full-scale invasion began in 2022. However, Ukrainian President Volodymyr Zelensky recently appealed for further supplies of interceptor missiles due to dwindling stocks. The spate of drone sightings across European airspace last year prompted discussions about a continent-wide "drone wall" of air defenses. Some European officials have accused Russia of being behind these drone sightings, a claim that Moscow has previously dismissed as absurd.