Turkey, Romania and Bulgaria started a joint mine-hunting force in the Black Sea on Monday to increase shipping safety, particularly for Ukrainian grain exports.

The Istanbul-led initiative, the first major joint action of Black Sea nations since Russia invaded Ukraine in February 2022, is aimed at defusing mines drifting into specific areas of the Black Sea as a result of the war.

Russia and Ukraine are key producers of grain, and the war has threatened the safe passage of shipments. Kyiv launched its own Black Sea export route last year after the collapse of a safe-corridor deal backed by Russia, Turkey and the United Nations. That has successfully boosted exports and helped the economy grow faster than forecast but the route remains risky.

Last year, a Russian missile strike near the key Ukrainian port of Odesa hit a commercial ship, killing a pilot and injuring others. A ship hired by agricultural giant Cargill Inc. was also damaged by an explosion while sailing from a Ukrainian port in the Black Sea in November.

Ukraine said in March that exports from its Black Sea ports had almost returned to pre-war volumes, after repeated attacks and disruptions since Russia’s full-scale invasion. Still, ports around Odesa face frequent strikes from Russia that continue to interrupt activity.

Ukraine has exported 37.4 million tons of agrarian products from Odesa, Chornomorsk and Pivdennyi since the opening of the marine corridor in August 2023, the Ukrainian Infrastructure Ministry said on its website last week.

Turkey, Romania and Bulgaria are all part of NATO. Yet their shipping force is being handled outside of NATO, in part to avoid escalating tensions with Russia.