The International Maritime Organization has warned shipowners that mines in the Black Sea are putting seafarers’ lives at risk.

The shipping regulator’s London-based secretariat said it continues to receive reports of mine sightings in the Black Sea off the coast of Turkey and Romania.

The IMO said the mines are the result of the “ongoing conflict in Ukraine”. It added that they “present a serious and immediate threat to the safety and security of crews and vessels operating in the region”.

The IMO is urging ships to navigate with caution. The United Nations organisation said it would be liaising with stakeholders in the region to address the problem.

Shipowners and managers have been calling on the UN to provide escorts for ships, but so far there has been no solution offered to tackle the threat of mines.

Nato said in an earlier statement that Bulgaria, Romania and Turkey are deploying vessels to locate and neutralise mines in the region.

The IMO warning suggests that ongoing efforts by littoral states to combat the problem may not have been successful.

The IMO’s safety alert comes a week after Nato issued a warning on mines in the western Black Sea.

It said: “The threat of drifting mines cannot be ruled out.”

It urged shipmasters to “take all precautions to mitigate the threat including avoiding floating objects”, and to “keep the forward area of the ship free of crew and use effective lookouts”.

UN secretary general Antonio Guterres is attempting to broker a deal with Russia to restart grain exports.

The removal of the mine threat will be required if grain exports from Ukraine are to be resumed.

Guterres told reporters last week: “We need to find a way to have the food production of Ukraine and the food and fertiliser production of Russia brought back to the global markets despite the war.”