A stretch of garden wall around an ancient villa in Pompeii collapsed Tuesday, just weeks after a house once used by gladiators crumbled.
Both disasters at the site of the 2,000-year-old city, which was buried beneath volcanic ash in 79 AD, were said to be caused by torrential rains.
The latest collapse has embarrassed the Italian government, which faces accusations that it is neglecting Italy's archeological sites.
"These collapses are a metaphor for the condition of Italy's heritage," said Pier Ferdinando Casini, the leader of an opposition party.
Pompeii officials said a 12-metre section of wall around the garden of the House of the Moralist had crumbled in several points.
The House of the Moralist wasn't touched by the falling debris and is not at risk, according to Pompeii excavations director Antonio Varone.
Its name comes from a list of etiquette rules inscribed on the walls of the dining room of the house, believed to have been owned by wealthy wine merchants. The rules include: "Do not have lustful expressions and flirtatious eyes for another man's wife."
The garden wall was heavily damaged by Allied bombing of the Naples area during the Second World War, but was rebuilt with original material. It had recently been reinforced, officials said.
The House of the Moralist stands only a few steps away from the Schola Armaturarum, where gladiators prepared for combat. That collapsed Nov. 6, and officials are still investigating whether it can be restored.
The tragedy prompted calls for the resignation of Culture Minister Sandro Bondi, who has presided over deep cuts to Italy's cultural spending.
A no-confidence motion against Bondi, scheduled for Parliament on Monday, has been postponed because of other legislation.
Bondi instructed ministry officials to keep monitoring Pompeii but warned against "useless alarmism."