Romanian authorities have recovered drone fragments in an inhabited area near the country’s southeastern border following overnight Russian strikes on Ukrainian ports along the Danube River, officials said on Tuesday.

The Ministry of National Defense said Romanian radars detected groups of drones near the NATO member’s airspace shortly after midnight on Tuesday. Emergency alerts were issued to residents in northern Tulcea County, which lies close to Ukraine’s border.

Adverse weather conditions prevented the deployment of fighter jets, the ministry added. However, military teams later located suspected drone debris about five kilometers inside Romanian territory.

Romanian Foreign Minister Oana Toiu confirmed the discovery on X (formerly Twitter), saying the fragments landed in a populated area. “These actions are part of a series of similar incidents and represent a characteristic of Russia’s ongoing war of aggression,” she said. “They also reflect Moscow’s continued provocations against the EU and NATO.”

Toiu warned that Romania and its allies “will not hesitate to raise the cost Russia pays for such reckless and illegal actions,” adding that new sanctions are being prepared to impose further pressure on Moscow.

Drone incursions into Romania’s airspace have grown increasingly frequent in recent months as Russia intensifies attacks on Ukrainian river ports across the Danube. Romanian officials have confirmed that drone fragments recovered in past incidents matched those used by the Russian military.

Both Romania and Poland have begun deploying new defense systems to counter Russian drones, amid concerns over repeated airspace breaches that have exposed NATO’s vulnerabilities and heightened tensions across Europe.