A Nato F-18 fighter jet operating on an air policing mission has shot down a drone that unlawfully entered Romanian airspace, marking the fourth unmanned craft brought down over the country this year, Romania’s defence ministry announced on Sunday.

The aircraft was initially detected by radar as it crossed into Romanian territory from neighbouring Moldova, 24 km north of the south-eastern city of Galati. Although Romania’s defence ministry did not specify the drone’s origin, Nato representatives suggested a Russian link.

A spokesperson for Nato military headquarters, U.S. Army Colonel Martin O’Donnell, reaffirmed that the alliance is constantly monitoring threats and stands ready to act.

He said: “Additional details regarding Sunday’s incident remain under investigation, but the drone appears to be Russian.”

Romania, a Nato member with a 614 km (381 miles) land border with Ukraine, has recorded numerous airspace incursions by Russian drones over the last four years, alongside floating sea mines threatening key Black Sea shipping and energy routes.

The F-18 jet, part of a Spanish Nato contingent deployed in Romania, “made radar contact with the target and received permission to engage”, the ministry said in a statement, adding that the drone was shot down safely at 5.01am (0201 GMT).

The ministry said that fragments from the destroyed drone appeared to have fallen in an uninhabited area between two villages.

In July, Romanian F-16 fighter jet pilots shot down three Russian drones breaching national airspace for the first time after dozens of such incursions since the start of Russia’s war in Ukraine.

In May, a Russian drone crashed into an apartment block in Galati during an overnight attack on neighbouring Ukraine, injuring two people.