Spokeswoman Daniela Leone said Saturday an external layer of a roughly two-meter (six-foot) section of wall collapsed at the northern end of the ancient ruins. Leone said it was of no artistic value and stressed that the wall itself remained standing. The area was closed to the public.

There were two collapses at the 2,000-year-old archaeological site last year, emphasizing concerns about the state of Italy’s cultural treasures.

Some 3 million people a year visit the ancient ruins of Pompeii, a teeming Roman city destroyed in A.D. 79 by a volcanic eruption.