The Ministry of National Defence reported that their Ukrainian counterparts stated the incident at the Port of Constanta on June 5 was an 'isolated' one, 'most likely caused by electronic warfare actions by the Russian Federation.'

'The Ukrainian Ministry of Defence has responded to the 14 questions posed by Minister Radu Miruta regarding the incident that occurred on June 5, 2026, at the Port of Constanta. The Ukrainian side confirmed that, on the afternoon of June 4, near Sevastopol—approximately 250 km from the Romanian coast—they lost contact with four Sargan-3000 naval drones (USVs) that were heading toward the eastern Black Sea. From that moment on, Ukrainian forces had no further control over the trajectories of the four drones and were unable to re-establish communication,' states a press release from the Ministry of National Defence (MApN) sent to AGERPRES on Friday.

The cited source states that on the morning of June 5, at 9:54 AM, the Ukrainian Navy informed the Romanian Navy of the danger posed by the USVs in the event of self-detonation and communicated the scheduled timeframe for the self-detonation of the four drones. A lack of communication with the drones made it impossible to cancel the self-detonation command.

'According to the Ukrainian side, this incident is an isolated one, most likely caused by the Russian Federation's electronic warfare activities,' the Ministry of National Defence notes.

Following this incident, the Ministry of National Defence states that it requested the Ukrainian side to open a permanent technical communication channel between the Ukrainian and Romanian Navies, and operational procedures were established for the parties to inform each other in a timely manner regarding risks in the Black Sea.

The Minister of Defence also states that he has officially requested the Ukrainian side to ensure that all naval drones launched into the Black Sea are programmed to self-destruct in a safe area—outside Romania's zones of interest—should they drift there for any reason.

On the morning of June 5, at 06:20, the Romanian Naval Authority's Maritime Coordination Center informed the Naval Component Command (CCN) of the presence of a floating object near Berth 78 in the Port of Constanta. The CCN notified the Coast Guard and the SRI (Romanian Intelligence Service) and alerted the 39th Diving Center to prepare EOD (Explosive Ordnance Disposal) teams.

At 09:54, Ukrainian authorities informed the Romanian side that they had lost control of four maritime drones in the Black Sea and that the drones were set to initiate their self-detonation sequence. Immediately upon receiving this information, the Naval Forces alerted the response teams at Berth 78, and personnel in the area were evacuated.

The explosion of the drone at Berth 78 occurred at 10:27. No casualties were reported.

Following the initial response, the Chief of the Naval Forces ordered an aerial reconnaissance mission over the sea using a Puma Naval helicopter. At the same time, the Maritime Hydrographic Directorate issued a notice to mariners regarding the presence of hazardous objects in the area. NATO Allied Maritime Command (MARCOM) was informed of the situation.

Around 11:00 AM, the Border Police reported that a Coast Guard vessel had observed a powerful explosion (a second drone) outside the port of Constanta.


Around 1:00 PM, the Coast Guard received reports from commercial vessels at sea indicating that two more powerful explosions (involving drones three and four) had been observed in the Black Sea.

At 14:35, the decision was made to halt intervention operations, following the cross-referencing of data provided by the Ukrainian side with field reports, as the destruction of the four drones was confirmed.AGERPRES (RO - writing by: Mihai Stoica, editing by: Florin Marin; EN - writing by: Catalin Cristian Trandafir)