A lump of coins, dated to 1,700 years ago, was discovered on Israel's west coast, the Israel Antiquities Authority (IAA) said Wednesday.

The six-kg coin lump was found at the HaBonim Beach in the eastern Mediterranean, about 25 km south of the northern city of Haifa, the IAA said.

The coins were found about 70 meters from the water, where in ancient times was a natural mooring used as a shelter for ships during storms, or for night anchoring.

The coins were probably bundled in a cloth bag, and it is still not clear from which metal they were made of.

"As a result of the oxidation in the marine environment, the coins merged together into a large lump," the researchers explained.

Given the large number of coins, they appear to have fallen from a wrecked ship, and were intended for trade, according to the IAA archaeologists.