The DDSL are warning clubs and people that are involved.
Abusive, threatening and racist behaviour has been reported at some children's football matches in Dublin.
The Dublin and District Schoolboys and Girls league has warned clubs for their antics.
They say those involved could be expelled from the league if they're found to be involved.
Some children's matches had to be abandoned due to overly aggressive behaviour.
DDSL warns members with expulsion if linked to attacks on referees or coaches
It comes as games, involving players as young as 9, were called off due to aggressive behaviour on the side-lines.
Is this something you have experienced?@andreagilligan wants to hear from you pic.twitter.com/q8mPLeqigC
— Lunchtime Live (@LunchtimeLiveNT) September 29, 2021
Katie is a parent who attended games that her son played in the league for a number of years.
She says sidelines can be an uncomfortable place to be watching from.
"Not just abusive language," she said. "But also abusive behaviour in the form of body language."
Katie said she has witnessed "parents getting very animated, aggressively on the sideline."
The behaviour she said isn't just limited to parents and their kids; that they target other kids too.