MADRID (AP) — The culling of nearly 900 cattle that were deemed unfit after spending more than two months at sea and on a ship has begun in the Mediterranean port of Cartagena, Spanish authorities said.

Spain’s Agriculture Ministry said Saturday that the cattle were being slaughtered “in strict compliance with Spanish and European norms regulating the health and wellbeing of animals.”

The ministry said it was carrying out the operation after the owners of the cargo ship transporting the livestock failed to respond in a timely manner to a ministerial order to cull the animals.

The cattle set sail from the Spanish port of Cartagena on Dec. 18 in the ship named Karim Allah. But the ship had to turn back after both Turkey and Libya refused to let the cattle disembark, reportedly because of suspicions about their health. The ship returned and docked in Cartagena's port on Feb. 25, where it has remained with the cattle onboard.

The ministry said the cattle originally left Spain with the proper health authorizations.

After returning to Spain two months later, an official inspection by government veterinarians deemed that the animals should be culled. Veterinarians judged them to be both unfit either for transport to another country or for their return to Spain. Of the 895 cattle which had left Spain in December, 864 returned to Cartagena after some had died during the weeks at sea.

Animal rights groups have denounced the culling.