Police are investigating after Cardiff residents woke up to "utterly sick and disgusting" far-right graffiti daubed on buildings.
The vandalism, which included Swastikas, the words "Nazi Zone" and offensive posters, was spotted by parents on the school run on Friday morning.
Greg Pycroft, from Grangetown, was on his way home from dropping his sons at nursery when he noticed the symbols and words on buildings near Grange Gardens, a small park to the west of the city centre.
Mr Pycroft said: "I live close to the park and have lived in Grangetown for over 10 years and this is the first time I've seen this kind of graffiti and vandalism.
"The scale and brazenness of it was shocking, but its proximity to the local kids catching their bus to school this morning was the more upsetting, since a large number will be teenagers and they'll know, or are beginning to understand the hatred behind that symbol.
"That was why I wanted it removed before home time this afternoon."
Mr Pycroft tweeted photographs of the graffiti, describing it as a "sad, sorry sight" and said he hoped it could be removed by Cardiff Council before the end of the school day.
Stephen Doughty, MP for Cardiff South and Penarth, replied to Mr Pycroft's tweet, saying: "Utterly sick + disgusting - will be raising with @swpolice @swpcardiff @cardiffcouncil immediately - far right extremism cannot be tolerated and not welcome in Cardiff. Full stop."
Cardiff Council said it condemned all graffiti "in the strongest possible terms" and was working with South Wales Police on the matter.
A spokeswoman said: "The offensive graffiti and flyposting will be removed as quickly as possible."
Meanwhile Chief Inspector Joe Jones, head of communities and partnerships at Cardiff Bay police station, said there would be a full investigation into the crime "with every intention of arresting and prosecuting the perpetrators".
He said CCTV and house-to-house inquiries were under way, while the posters would be sent for forensic examination.
"Cardiff is a modern, vibrant and safe multi-cultural city where people of different religions, faiths and cultures live side by side in peaceful harmony and have done for many, many years," he said.
"The vandalism of public buildings with such abhorrent racist graffiti is totally unacceptable criminal behaviour and it will not be tolerated.
"The offensive graffiti is in the process of being removed and there will be a full investigation into this crime."
He urged anyone who had information about the incident to call the police on 101 or contact Crimestoppers anonymously on 0800 555111.