SKOPJE, North Macedonia (AP) — Police in North Macedonia say they have detained five men, including two Chinese citizens and a customs official, on suspicion of smuggling a critically endangered species of eel.

Police said Thursday that four of the suspects allegedly purchased 60 kilograms (132 pounds) of juvenile European eels, known as glass eels, with estimated value of 120,000 euros ($135,000), in Bulgaria for a buyer in Malaysia.

The European eel is classified as critically endangered by the International Union for Conservation of Nature.

Authorities discovered the live cargo hidden in a car in which the four were travelling during a routine highway control. Police say the eels were to be flown from Skopje's international airport to Kuala Lumpur. The customs official is accused of granting the four a free pass from Bulgaria into North Macedonia.