NATO-member Romania broadened Thursday a restricted flight zone following the discovery of drone debris on its territory near Ukrainian ports on the Danube river that had been attacked by Russia.
An order from the Romanian defence ministry banned piloted and unmanned aircraft from flying within 30 kilometres (19 miles) of the border with Ukraine at altitude of less than 4,000 metres.
The two countries share a border of over 100 kilometres along the Danube as it nears the Black Sea.
Ukraine has a major port located along the river at Izmail, with grain facilities there coming under repeated attack in recent weeks.
NATO said Wednesday that fragments of Russian-style drones have been found on Romanian territory for the third time in less than two weeks.
Romania has had an eight-kilometre exclusion zone for flights of less than 1,000 metres in place since Russia's invasion last February 2022.
NATO Secretary General has said there was "no indication of intent to hit NATO" but that the Russian strikes were "destabilising".
Since the start of Russia's invasion of Ukraine in February 2022, NATO has been trying to prevent the war from spreading to its member countries.