Feb. 10 (UPI) -- Spanish police at Madrid-Barajas Airport discovered a group of Chinese passengers had packed in their luggage several hundred pounds of an endangered species of eel, authorities said.
The 683 pounds of young eels were to be flown to Asia in the smuggling attempt, according to a Civil Guard announcement.
About 550 pounds of eels were packed in several boxes similar to Styrofoam with water and ice to keep the species alive until the final destination, officials said. They were hidden in packages declared as barnacles destined for Vietnam, held in the airport's cargo terminal.
Later, officials said they found another 130 pounds in suitcases on a Hong Kong-bound flight.
The European eel has been declining because of the loss of its natural habitat and illegal fishing. It is considered critically endangered.
"Thanks to the vigilance that is carried out by the Civil Guard and Customs Surveillance of the Tax Agency, during the last week two actions have been carried out that have allowed to intervene the (683 pounds) of [eels]," according to the Civil Guard statement.
The animals were taken to the Nature Protection Service and were later placed in the Gipuzkoa Oiartzun and Oria rivers.