A series of raids conducted across Asia, Africa and Europe resulted in more than 300 arrests and over 600 seizures of assorted wildlife contraband — from several tons of ivory and rhino horns to whale ribs and sea horses, authorities said Thursday.

Law enforcement agencies from 62 countries took part in the operation codenamed "COBRA III" along with international organizations such as Interpol and Europol, according to a statement released by organizers in Bangkok.

Those arrested in the May 4-27 operation included eight trafficking kingpins identified as three Chinese, four Vietnamese and an Indian, said the statement from Operation Cobra, organized by the Southeast Asian-based ASEAN Wildlife Enforcement Network, which works with regional officers from wildlife, customs, police and other agencies.

This year's operation "was the most successful so far," said police Capt. Vatanarak Suranartyuth, a senior official with the network. It was the first time that European Union countries participated.

"The trafficking of endangered species remains a problem in the EU and beyond," said Europol Director Rob Wainwright. "We will continue our efforts to fight these cruel crimes, to ensure a safe environment for endangered species in Europe and all over the world."

The seizures highlighted the scope of wildlife trafficking:

— Over 12 tons of elephant ivory, including 4.3 tons in Thailand that came from the Democratic Republic of Congo and 3.1 tons from Kenya. Other ivory seizures came from Singapore (3.7 tons), Mozambique (1.3 tons) and Uganda (0.6 tons).

— 126 rhino horns from Mozambique, Vietnam, Namibia and Kenya.

— 1 ton of abalone seized in South Africa.

— A speedboat impounded in Hong Kong containing live tortoises, lizards, spiders, 550 pounds of pangolin scales and about 22 pounds of bornbill beak.

Europol said that EU authorities seized:

— 44 pounds of live leeches and 55 pounds of coral in Bulgaria, plus 200 pounds of coral in Spain.

— 10,000 dead sea horses and over 400 live turtles and tortoises in the United Kingdom, plus 300 more in Croatia.

— 16 whale ribs in the Netherlands.