The cargo ship Khoryv, flying the flag of the Comoros, sank on Friday 23 October, 13 nautical miles off the Romanian port of Constanta, after a suspected drone strike, sources close to the investigation say.
There were 13 people on board, 10 Ukrainians and three Azerbaijanis. Nine were rescued, one died and three are missing.
The ship went down east of Constanta, outside Romania's territorial waters but right at their edge.
The crew sent an SOS in the morning because of a fire on board. The signal reached the Maritime Coordination Centre of the Romanian Naval Authority at about 10:00. The centre asked the Romanian maritime rescue agency (ARSVOM) for help at 10:15.
Earlier, Romania's interior ministry said the ship was badly damaged, had capsized and was at immediate risk of sinking.
Another cargo ship in the area pulled the nine survivors and the dead sailor from the water. The survivors were then moved to a coast guard vessel. The Romanian Naval Authority said ships from ARSVOM and the interior ministry set out right after the alert. ARSVOM said the rescue vessel SAR ARTEMIS left from Pier 78 in Constanta.
A coast guard vessel and an ARSVOM ship are still searching for the three missing men.
A helicopter from the interior ministry's General Inspectorate for Aviation is on standby and will join the search if needed once the weather allows. For now, bad weather and poor visibility rule out help from the air. A Black Hawk helicopter was also requested, but heavy rain and rough weather off Constanta kept it from taking off.
The ship sank even though NATO has stepped up surveillance over the Black Sea. A US Boeing P-8A Poseidon aircraft is patrolling above it from Varna airport.
"This is an event in the escalation that Russia is carrying out," Romanian president Nicusor Dan said. He said Romania will get more military equipment after talks in the Supreme Council of National Defence and at a NATO meeting.
Defence minister Stefan Radu Oprea said the incident happened outside territorial waters, so the coast guard is handling it. He added that the army can step in when drones enter Romanian territory.
Reserve rear admiral Sorin Learschi says such attacks put shipping, trade and the insurance market at risk.
The Supreme Council of National Defence has set new strategic priorities for Romania's security in the Black Sea, the Presidential Administration said. It said threats to shipping and critical infrastructure have grown because of Russia's aggression against Ukraine. The council reviewed the steps taken so far and what is needed to build up Romania's ability to monitor the sea and respond. The aim is to protect territorial waters, critical infrastructure and commercial shipping.
The priorities are faster development of sea surveillance, the fight against naval mines, and a better response to drones that enter Romanian air and sea space without permission. The council also wants regular joint drills between agencies, updated response plans and coordinated action in complex incidents that affect shipping, economic sites and the marine environment at the same time.
On 6 October, drones hit the cargo ships Alfa Watan and Able in Bulgaria's exclusive economic zone. Alfa Watan sank, and all 18 sailors from Able were rescued, we reported on 9 October.
A similar case involving another Comoros-flagged ship happened off Sulina about 10 days ago.