A memorial sculpture commemorating the victims of Bloody Sunday has been vandalised in the Bogside.
Work on the carved brick sculpture was almost completed when it was damaged at the Gasyard on Saturday night.
Local community worker Declan McLaughlin said he was "disgusted".
"There is a very small group of teenagers here who are just running rampant most nights of the week. This isn't the first piece of vandalism they've been involved in," he added.
"It's a disgrace.
"This monument was designed by young people, was paid for by local people and this is an attack on this community."
Brian McGee, who has been involved in the project, said he cannot understand why the art work was vandalised.
"There is various damage, the top of the sculpture is completed broken, the top four courses of it have been knocked off."