POLICE have appealed for witnesses after graffiti appeared at Murtoa showground between last Friday and Saturday.
Vandals wrote obscene words on the oval scoreboard and netball court, using spray paint and markers.
Rupanyup Leading Senior Constable Darryl Anderson said the vandalism was a continuing problem. A private house window had also been ruined with obscene graffiti.
"This graffiti is directed at certain people and is extremely offensive and obscene," he said.
"This is the act of weak, cowardly vandals trying to intimidate and bully other people."
Leading Sen Const Anderson said he also believed that text messages sent from a public telephone near Murtoa Medical Clinic were related to the graffiti.
He said the text messages were of a similar offensive and obscene nature and were sent between Friday and Saturday.
"This bully behaviour is not the type of thing that should be in country communities," he said.
"If the people involved want to negate the damage they have caused, they should call police."
Leading Sen Const Anderson said anyone with information could call Rupanyup Police Station on 5385 5078.