The Baltic states are discussing the construction of bomb shelters as Russian drones are being used heavily in Ukraine, Politico reported.

According to the outlet, the debate reflects growing concern on NATO’s eastern flank over the scale and intensity of Russia’s drone campaign. Politico notes that the Baltic states fear their small territory and densely populated urban areas would leave little room for error in the event of a major attack.

The anxiety is no longer limited to military planning. The report says it has also reached the Baltic real estate market.

Last week, Polish Prime Minister Donald Tusk said the rising number of drone incidents in the Baltic region was making the threat of war in Europe real.

Since late March, Ukrainian UAVs have been detected several times in the airspace of Latvia, Lithuania and Estonia. Moscow later issued a separate warning to the Baltic states.

On May 19, Russia’s Foreign Intelligence Service said Kiev was preparing a new wave of terrorist attacks against Russian rear regions. The agency claimed that Ukrainian forces planned to use Baltic territory to launch drones and reduce their flight time to targets.