Navy crews have destroyed on the spot or pulled from the water parts of more than 100 drones this year alone. Rear Admiral Kiril Mihaylov, the navy commander, said this at the Sea Station in Varna, where he welcomed back ships from the latest mission of the international Black Sea mine countermeasures group.

Of the pieces found so far, 35 proved dangerous and were destroyed. Others have no warhead but still threaten shipping, and were also removed from the sea. The navy has also destroyed six floating mines in Bulgarian waters.

Two patrol ships are now checking shipping lanes for mines and for drone debris that must be destroyed. A Poseidon maritime patrol aircraft based in Varna is also watching the sea. "This is already support from the allies," Mihaylov said, adding that the plane will keep flying missions from there.

The navy is working with all branches of the Bulgarian Army to step up monitoring and control of traffic in the Black Sea. It also uses drones from the Land Forces and the Joint Special Operations Command.

Mihaylov said the navy is doing a good job of surveying Bulgaria's waters and keeping them safe. "We continue our efforts both in a coalition format with our allies from neighbouring countries and on our own," he said.

Bulgaria is in constant contact with neighbouring countries, NATO's Allied Maritime Command and the navy commands of the US and France.