Romania’s Defense Ministry said early on Wednesday that it scrambled fighter jets overnight as the Russian military carried out a series of drone attacks near its shared border with southern Ukraine.The defense ministry said in a statement that two F-16 aircraft took off at 2:19 a.m.

local time from the 86th Borcea Air Base, located around 126 kilometers east of the capital Bucharest.

According to the statement, the fighter jets were tasked with monitoring “the aerial situation.”Around the same time, Romania’s Tulcea County — which borders southern Ukraine’s Odesa region — was put on alert as Russian forces were said to have been carrying out drone attacks “against certain targets” near the NATO member’s border with Ukraine.

Authorities did not specify where those attacks had taken place.Romanian authorities lifted the alert for Tulcea County less than two hours after it was introduced, and the two F-16 fighter jets that had been scrambled earlier returned to base at around 4:20 a.m.

local time. “The Ministry of National Defence has ordered measures to conduct investigations in the field, in the vicinity of Plauru, to search for possible objects that have fallen on the national territory,” the defense ministry’s statement said, referring to a town located just 300 meters from the Ukrainian city of Izmail on the Danube River.Since the start of Moscow’s full-scale invasion of Ukraine, Romania has on multiple occasions discovered drone debris near the border with its neighbor to the north.

Authorities in the EU-member state have introduced measures to protect people living in and around the border area, including constructing air-raid shelters.