Officer Dang Van Hanh said the live snakes were taken to a wildlife rescue centre near the city where they were checked before being released back into the wild.
King cobras are the world's longest venomous snake and grow up to 5.5 meters feet.
The meat of the king cobra is considered a delicacy by some in Vietnam, though hunting and trading the snakes is banned. The snakes are also sometimes preserved in traditional medicines.
The snakes, which were kept in green sacks, were seized on April 19, 2013.
Hanh said the driver told officers he was paid to transport them. Local media reported he was paid less than Rs1700.