NATO member Romania scrambled F-16 fighter jets in response to a Russian drone attack, the country's Ministry of National Defense announced.
Officials said there was no violation of NATO airspace by Russian weapons and that two aircraft were deployed to "monitor the border area with Ukraine."
The proximity of the Russian strikes to NATO territory has raised security concerns in the region, raising questions about the alliance's preparedness and deterrence capabilities.
According to Article 5 of the NATO treaty, an attack on one country can trigger a collective response, which puts additional control over events near the borders of Alliance.
The Romanian Ministry of National Defense stated: "On Friday, January 2, the surveillance system of the Ministry of National Defense identified drones launched by the Russian Federation towards Ukrainian ports on the Danube near the border with Romania".
"At around 11:50 a.m., two F-16 fighter jets from the 86th Air Base in Fetești were scrambled to monitor the border area with Ukraine, in the northern part of Tulcea County. At 12:00 p.m., the population in the northern part of Tulcea County was warned via the RO-Alert message".
"The state of alert ended at 12:22 p.m. "No unauthorized violations of national airspace were recorded during the mission."
This comes after Russia accused Ukraine of killing 24 people and wounding at least 50 others on New Year's Eve in a Russian-occupied village in Ukraine's Kherson region.
Kiev has denied Moscow's claims of "war crimes", calling them a ruse aimed at derailing ongoing peace talks and saying only Russian military forces or energy facilities were attacked.