A children's playground has been shut after dog excrement was "smeared" on the floor and play equipment.
The public playground in Duffryn , Newport, was closed after the incident was reported to Newport City Council.
The council said staff had never come across "such atrocious behaviour" before.
A council spokeswoman said Gwent Police had been informed and urged members of the public to contact officers with information about the incident.
The contaminated play area is currently shut to the public on health and safety grounds.
The council said a deep clean of the area and equipment will now take place before the park reopens.
A social media post about the incident attracted a number of comments from concerned residents.
One asked: "What on earth is wrong with people?"
Duffryn Dusters Community Clean Up said: "Absolutely disgusting, a lot of work has been done to increase the number of bins, but yes more are needed.
"[It] does not deflect the reckless attitude of these people doing this, however."
A council spokeswoman said: "To do this to a children’s play area is totally unacceptable.
"The whole play area is contaminated so has had to be closed before a deep clean can take place.
"If anyone has information as to who has committed this anti-social act please inform Gwent Police on 101."
