The Romanian Ministry of National Defense (MApN) has confirmed that four Ukrainian naval drones, identified as Sargan-3000 models, entered the Black Sea and subsequently detonated near the Port of Constanța on June 5, 2026, following a loss of communication. According to official reports from the Ukrainian Ministry of Defense, the loss of control occurred near Sevastopol on June 4, 2026, due to suspected Russian electronic warfare, rendering the drones’ self-destruct sequences impossible to abort.
How did the naval drones reach the Port of Constanța?
Ukrainian forces lost contact with four Sargan-3000 uncrewed surface vessels (USVs) on the afternoon of June 4, approximately 250 kilometers from the Romanian coastline. The Ukrainian Ministry of Defense stated that once communications were severed, the vessels drifted without further input or control from their operators. By the morning of June 5, at 09:54, the Ukrainian Naval Forces notified the Romanian Naval Forces of the potential danger, providing the pre-programmed timeframes for the drones’ automatic detonation sequences.
The Romanian Naval Forces utilized a Puma Naval helicopter to conduct aerial surveillance of the Black Sea immediately following the identification of the drifting drones to ensure no further threats remained in the vicinity.
What was the timeline of the security incident?
The sequence of events began at 06:20 on June 5, when the Maritime Coordination Center of the Romanian Naval Authority identified an object near Pier 78 in the Port of Constanța. According to the MApN, the following timeline was recorded:
- 06:20: Port authorities identified a floating object, triggering alerts for the Coast Guard and the 39th Diving Center.
- 09:54: Ukrainian authorities officially warned Romania of the four drifting USVs and their impending self-detonation.
- 10:27: The first drone exploded at Pier 78; personnel had been successfully evacuated.
- 11:00: A second explosion was reported by a Coast Guard vessel outside the port.
- 13:00: Commercial vessels reported two additional explosions in the open sea.
- 14:35: Operations ceased after all four drones were confirmed destroyed.
What changes are being made to maritime security protocols?
In response to the incident, the Romanian Ministry of National Defense has requested a permanent technical communication channel between the Romanian and Ukrainian navies. Minister of National Defense Radu Miruță formally requested that all future naval drones launched in the Black Sea be programmed to self-detonate in “safe zones” well outside of areas of Romanian interest. Additionally, the MApN is currently collaborating with the Ministry of Internal Affairs and the Ministry of Transport to refine the legislative framework governing both military and civil port security.
To stay updated on maritime safety notices, mariners should regularly consult the official Romanian Naval Authority website for Notices to Mariners (Aviz către navigatori).
Frequently Asked Questions
Were there any casualties during the drone explosions?
No. According to official statements from the Romanian Ministry of National Defense, there were no casualties reported. Personnel were evacuated from Pier 78 before the first detonation occurred at 10:27.
Why couldn’t the drones be stopped?
The Ukrainian Ministry of Defense confirmed that the loss of communication, likely caused by Russian electronic warfare, made it impossible for operators to cancel the pre-set self-detonation commands once the drones had drifted off course.
Is this considered a recurring threat?
Ukrainian officials characterized the incident as an isolated case. However, Romania has since implemented stricter monitoring and coordination procedures to mitigate risks to port infrastructure.
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