A primary school has banned parents from all future sports days after what it said was bad behaviour.
In a letter to parents seen by BBC Wales, the head teacher at Pentrebane school in Cardiff said angry parents could be threatening and intimidating.
Sheena Duggan added some staff had been sworn at in front of children.
The letter was sent the day after the school's annual sports day last week, saying the behaviour had "worsened" over the last few years.
A father who attended the sports day, and asked not to be named, said: "I've honestly no idea what happened to spark this off.
"It was a really nice day, all the children were involved, everyone was cheered on and got a round of applause.
"Some parents were competitive, as you might expect, but none were aggressive or threatening towards staff that I could see."
In her letter, Mrs Duggan wrote: "As you know the safety, happiness and wellbeing of our pupils, your children, is paramount and so with that in mind I have made the difficult decision that future sports days will not be open to parents.
"It is very sad but I feel strongly that my staff and pupils do not come to school to be exposed to the bad behaviour of a small minority of adults."
The parent added Mrs Duggan was "well respected" and "takes no nonsense", and "something particularly bad must have happened" for this decision to be made.
"But no-one I know has any idea what it is," he added.
"There's lots of unhappiness from parents who don't think they should be punished for the bad behaviour of others."
BBC Wales has made attempts to contact the school for comment.