Drones spotted in Bulgaria and Germany raise concerns about Russian escalation - Al Jazeera

Drones spotted in Bulgaria and Germany raise concerns about Russian escalation  Al JazeeraUkraine denies targeting Bulgaria after drone explodes near gas pipeline  CBS NewsA drone likely from Ukraine explodes in Bulgaria near a gas pipeline  AP NewsBulgaria says drone explodes in its airspace, no damage  ReutersBulgaria Says Drone Crashes Near Romanian Border, Gas Pipeline  Bloomberg.com