Romania sent out fighter jets to track drones which breached its territory near the border with Ukraine early on Tuesday, and one was still advancing deeper into the country, the defense ministry said.

Axar.az reports, citing Reuters, the ministry said it initially scrambled two Eurofighters – part of German air-policing missions in Romania – which tracked a drone in the southeastern county of Tulcea before it re-entered Ukraine.

The army later scrambled two Romanian F-16 fighter jets after radar showed a second airspace breach in the county of Galati. The planes tracked it moving inland towards the county of Vrancea, the ministry said.

Residents of all three counties were warned to take cover.