Rescuers were struggling to save 14,600 sheep after the cargo ship they were being carried on capsized in the Black Sea off the coast of Romania.

The Queen Hind, bound for Saudi Arabia, overturned on Sunday shortly after leaving Romania’s Midia port.

The crew of 20 Syrians and one Lebanese were rescued, together with 32 sheep, two of which were pulled from the water, said Ana-Maria Stoica, a spokeswoman for the rescue services.

“The rescue operation is ongoing ... We hope that the sheep inside the ship’s hold are still alive,” she told AFP.

Rescuers supported by the military, police and divers were trying to right the Palau-flagged ship and pull it to the port, she said.

Sheep rescued from the capsized livestock transport vessel Photograph: -/IGSU Romania/AFP via Getty Images

Romania’s main livestock breeder and exporter association, Acebop, called for an urgent investigation.

“Our association is shocked by the disaster,” said the Acebop president, Mary Pana. “If we cannot protect livestock during long-distance transports, we should outright ban them.”

Gabriel Paun of the NGO Animals International alleged that the ship had been overloaded. He added that the Queen Hind had already had engine problems last December. “An investigation must be opened without delay,” he told AFP.

Romania joined the EU in 2007 and is one of its poorest members. It is the bloc’s third-largest sheep breeder, after Britain and Spain, and a top exporter, primarily to Middle Eastern markets.

Activists have labelled the livestock transport vessels “death ships”, saying sheep risk being cooked alive on board during the hot summer months. About 100 depart Midia every year.

In July, Vytenis Andriukaitis, then European commissioner in charge of health and food safety, demanded that Bucharest stop the transport of 70,000 sheep to the Gulf, citing animal welfare. He has asked the European commission to investigate Romania’s practices.