Venice authorities are cracking down on tourists who are skinny dipping and destroying historical landmarks: 'The city must be respected'

• The facade of the Redentore church in Venice, Italy, was vandalized last week.
• This week, two American tourists were caught skinny dipping in a culturally significant canal.

Authorities are cracking down on tourists who are skinny dipping in canals and putting graffiti on ancient churches in Venice, Italy, CNN reported.

The outlet reported that two American tourists were caught on camera skinny dipping in a canal in the residential district of Castello, which is a cultural site designated by the United Nations.

Authorities are still searching for the two tourists, the outlet said.

The incident comes a week after the façade of the Redentore church was vandalized with a pink background followed by random writing on top of it, local paper La Nuova reported. The church was designed by Renaissance "starchitect" Andrea Palladio.

Venice Mayor Luigi Brugnaro said the vandalism "stained a symbolic place of the Venetians' devotion and their traditions."

"Those responsible must not go unpunished, they must 'pay'!" he said in a tweet.