SOFIA, July 14 -- A joint naval exercise of eight NATO members began on Friday in Bulgaria's Black Sea zone, officials said.

The joint naval exercise Breeze involved 20 ships, one submarine, four airplanes, two helicopters and 1,700 troops from the eight NATO countries

The Royal Navy's air defense destroyer HMS Duncan, Turkish frigate Yildirim and Romanian frigate Regele Ferdinand from the Standing NATO Maritime Group Two, Bulgarian frigate Drazki and Greek fast attack craft Ritsos are some of the vessels involved in the drill, the Bulgarian Navy said in a statement.

A U.S. P-8 Poseidon patrol plane and a mobile Italian maritime traffic control center as well as staff officers from Poland also participate in the exercise, along with representatives of 21 Bulgarian agencies, local authorities and NGOs, the statement said.

The main idea of the 10-day exercise led by Bulgarian Navy, was to improve interoperability and interaction during a maritime crisis response operation, and certify the frigate Drazki according to the NATO Maritime Evaluation Programme (MAREVAL), the statement said.

Bulgarian Navy held Breeze drill for the first time in 1993, with the participation of three visiting warships including a U.S. frigate and two Turkish minesweepers.