Indonesian authorities said on Wednesday they had seized five komodo dragons and dozens of other animals being sold on Facebook, as the country battles to clamp down on the illegal wildlife trade.

The vast Southeast Asian archipelago nation's dense tropical rainforests boast some of the highest levels of biodiversity in the world and it has for years been a key source and transit point for animal trafficking.

Five smugglers, identified only by their initials, were arrested in Semarang and Surabaya on Java island for allegedly trafficking the komodos - the world's biggest lizard - along with bearcats, cockatoos and cassowary birds.

"The suspect VS sold the komodos online through Facebook," East Java police spokesman Frans Barung Mangera said in a statement.