Romania on Friday said a Russian drone carrying explosives crashed in the eastern city of Galați, causing a fire on the roof of a residential apartment block.
The building was evacuated and two people sustained minor injuries, Oana Toiu, Romania's foreign minister, said.
"Two aircraft and a helicopter belonging to the Romanian Air Force were scrambled when Russian drones appeared on the radar, they had permission to shoot," she continued, adding that it was "a serious and irresponsible escalation" by Moscow.
"Romania has informed European member states, the Allies and the NATO Secretary General of the circumstances and has requested measures to accelerate the transfer of anti-drone capabilities to Romania," she said.
Romania has since summoned the Russian ambassador to the headquarters of the Ministry of Foreign Affairs.
The incident has sparked strong criticism from leaders across Europe.
EU Commission President Ursula von der Leyen said on Friday that Russia had "crossed yet another line" and vowed to continue to put pressure on Moscow.
"We stand in full solidarity with Romania and its people," von der Leyen said, adding that the EU was prepping a 21st package of Russian sanctions.
In a statement, NATO condemned Russia’s "recklessness" and said the alliance would strengthen its defences against "all threats, including drones".
NATO's eastern flank has been plagued by errant drone incursions in recent weeks, with a wave of incidents taking place across Estonia, Latvia and Lithuania.
Moscow has accused the Baltic states of allowing Ukraine to use their airspace to carry out attacks on Russian soil and threatened to take action against them.
The Baltic governments issued a joint statement alongside Nordic allies saying they "firmly reject Russia’s blatant disinformation campaign and false claims".
"The Nordic-Baltic countries have never allowed their territory or airspace to be used for these attacks against targets in Russia," the statement read.