A Romanian air force F-16 fighter jet shoots at a drone flying over the Black Sea near Sulina on 17 October.

Mounting anxiety as Russia’s war on Ukraine reaches Nato’s borders with targeting of vessels transporting agricultural cargo Nato is deploying additional military assets to the Black Sea amid the recent deadly escalation of Russian attacks on merchant shipping, as five more vessels were attacked on Tuesday.

Russia’s military said it struck three cargo vessels in Ukraine’s port of Reni and two other cargo vessels en route to Odesa.

Russia’s targeting of vessels taking grain and other agricultural cargoes from Ukraine’s ports – central to the country’s economy – have brought the conflict to Nato’s borders, with a new high-risk designation used by the London shipping insurance market now covering all of the Black Sea save for the territorial waters of Romania, Bulgaria and Turkey.

With a sharply rising death toll among civilian seafarers that has made Black Sea routes the world’s most dangerous, Nato announced the defensive military alliance would add more surveillance assets in the region.

Nato’s spokesperson, Allison Hart, said: “Today, Nato ambassadors met in the North Atlantic Council to discuss security in the Black Sea. Nato has already strengthened our posture along the eastern flank, including with counter-drone capabilities. Nato will be sending additional assets to the region, including support for surveillance, reconnaissance, and forensics.”The deployment will include maritime patrol aircraft, radar systems, drones and intelligence personnel. There is mounting anxiety about the increasing overspill from Russia’s war on Ukraine and the potential for further friction with Nato.

Concern has been growing after alleged Russian attacks that have increasingly edged into the territorial waters and exclusive economic zones of Bulgaria and Romania Romania deployed jets over the weekend to shoot down two suspected Russian drones over its territory. A vessel that was hit by a drone in the Black Sea this month.

Romania’s defence minister, Radu Miruță, said the drones were probably latest generation Russian drones, flying at speeds similar to fighter jets.

“The ones from last night were flying at 450 km/h, which leads us to think they were Russian-made Geran-4 drones with a turboprop engine,” Miruță said. “This is the first time we’ve shot down drones like these.”Romania has recorded 35 unauthorised drone incursions so far this year, compared with nine in 2025. Romanian forces have downed six drones this year, compared with zero last year.

Last week, two chemical tankers were hit by drones near Romania’s Black Sea coast, the latest in a series of attacks that have highlighted the risks to commercial shipping on Nato’s eastern flank. Both vessels were anchored near the Sulina canal, which links the Danube River to the Black Sea and is an export route for Ukraine.

At least five other cargo ships have been hit near the coasts of Romania and Bulgaria in the past two weeks, with 23 sailors reported dead or missing. Most of those incidents occurred outside Nato territorial waters. Four rescued sailors arrive in Bulgaria after their vessel sank following an attack in the Black Sea this month.

Amid mounting concern, Bulgaria has asked Nato for the deployment of combat aircraft and anti-drone systems to its territory. On 18 October, France sent a maritime reconnaissance aircraft to Romania.

The maritime insurer and risk analyst Ambrey has said there is no end in sight to the threats to Black Sea cargo shipping, including grain and oil, and that insurance prices for passage of the waters have rocketed.

Tomas Alexa, a senior analyst at Ambrey, said last week his company had noted a sharp increase in the tempo of attacks beginning in July. Russian forces are estimated to be responsible for 80% of them.

The recent loss of life, he suggested, had been exacerbated by “double tap” attacks involving aerial and surface drones, the latter often carrying up to half a tonne of explosive payloads. Smaller vessels that primarily use the Danube canal system have sunk rapidly.

“While attacks against merchant vessels in the Black Sea are not new, we are seeing an escalation both in terms of the number of attacks and in the geographical scope,” Alexa said.