Over the past months, Ukrainian drones have crashed into the chimney of a power plant in Estonia, hit empty fuel tanks in Latvia and been shot down by Romanian fighter jets stationed in Lithuania.

For the first time in a NATO and European Union capital, Lithuanians were pictured sheltering in underground car parks in Vilnius on Wednesday, as authorities warned of unidentified drone activity.

No one has died or been injured recently, but the increasing airspace incursions have prompted some Baltic ministers to chastise Ukraine for the violations. In Latvia, officials’ handling of the stray drones led to a political crisis that triggered the collapse of the government earlier this month.