Archaeologists have discovered two iron ship anchors off Mexico's Gulf Coast that they say date back 500 years and could have belonged to Spaniard Hernan Cortes' fleet, which landed in 1519 before overthrowing the Aztec empire.

The anchors, found on the ocean floor near the former Spanish settlement of Villa Rica in southeastern Veracruz state, are well preserved and resemble those made in the 1500s, Mexico's National Institute of Anthropology and History (INAH) said on Monday.

Their discovery, along with an anchor believed to be from the 15th century that was found last year, has reassured archaeologists that they are on track to find more artifacts documenting the European invasion of Mexico.