Romanian coast guards rescued 157 Iranian and Iraqi migrants, including 56 children, from a ship drifting on the stormy Black Sea on Wednesday, the fifth incident of its kind in the past month.

The increasing number of migrants risking the journey from Turkey to Romania has raised fears that the Black Sea is becoming a new route for migrants trying to reach Western Europe.

The ship was towed to the Black Sea port of Midia on Wednesday before dawn after a 15-hour rescue operation by the Romanian Coast Guard and Navy.

Deputy coast guard commander Laurentiu Cristian Cicu described the rescue operation as difficult and said the people had been in grave danger.

“Waves were over two metres high in that area,” he told journalists. “The people in the boat were constantly in danger of drowning, as the boat could have sunk at any time,” he explained.

Authorities initially spotted the ship outside Romanian territorial waters on Tuesday after it sent a distress signal.

A border police press release issued on Tuesday night said two coast guard boats were dispatched – but high waves and winds hampered rescue efforts at sea.

The number of people trying to reach Romania from Turkey via the Black Sea has increased sharply in the past month.

On Saturday, coast guards from both Romania and Bulgaria rescued 217 migrants in two boats in the Black Sea.

Turkish authorities announced on Sunday that over the weekend they had stopped 313 migrants on the Black Sea attempting to reach Balkan countries.

On September 3, Romanian coastguards stopped a fishing vessel carrying 87 migrants in the Black Sea sailing toward the coast.

In August, coast guards halted a fishing boat carrying 70 migrants suspected of trying to illegally enter Romania.