Russia has scaled down the festivities honoring its navy citing security concerns as continuing Ukrainian drone attacks posed a challenge the Kremlin.

NATO aircraft were scrambled Sunday night to respond to a Russian attack on Ukraine, the Polish military said Monday.

Five people have been killed in overnight strikes in Russia and Ukraine, as the two sides continue to trade drone attacks. Ukrainian officials said on Saturday that more than 200 drones and almost 30 missiles were fired by Russia, with most targeting Dnipropetrovsk where three people died.