Bucharest: A sea drone exploded in Romania’s Black Sea port of Constanta on Friday without causing casualties, marking the latest security incident in the NATO member state as the war in neighbouring Ukraine continues to spill close to its borders.

"The maritime drone discovered this morning, June 5, in the Civil Port of Constanta ... self-destructed around 10:30 am local time (0730 GMT) without causing any casualties," the country's defence ministry said in a statement.

The incident comes just a week after a Russian drone involved in an attack on Ukraine veered off course and struck an apartment building in eastern Romania, injuring two people on May 30.

According to Romanian authorities, the drone was tracked overnight by radar in Romanian airspace before crashing onto the roof of a residential building in the Danube port city of Galati, triggering a fire. The two injuries were minor, and several residents were evacuated.

The latest explosion in Constanta underscores growing concerns about the conflict's proximity to NATO territory. Romania, which shares a border with Ukraine and has strategic access to the Black Sea, has repeatedly reported drone fragments and incursions linked to the war since Russia launched its full-scale invasion of Ukraine in February 2022.

It was the latest in a series of drones — from both Russia and Ukraine — to hit a NATO member since Moscow launched its full-scale invasion in February 2022.