Two American tourists have been ordered to appear in court for carving their names into the Colosseum, the latest act of vandalism sustained by the ancient monument at the hands of tourists.

Carabinieri Captain Lorenzo Iacobone said Monday two tourists from California, ages 21 and 25, were picked up Saturday for carving their names eight centimeters (three inches) high into an upper level of the Colosseum. They were freed later but will face trial for aggravated damage to a monument.

Iacobone said the young women apologized for the vandalism, but he said such acts "are extremely serious, and no one considers the damage they are creating."

A Russian tourist who carved his initials into the Colosseum in November was handed a four-month suspended sentence and a fine of 20,000 euros.