A 16-year-old boy was assaulted in Broughty Ferry on a night which saw dozens of youths gathering in the area.
Police were called after reports of a gang of young people hanging about.
The assault came on the same night as a Broughty park was left covered in litter.
Paul Meyler, 51, said that there were about 60 youngsters hanging around.
He said: “They started to congregate on the corner outside my house at 7pm and were a bit rowdy, as someone had apparently been hurt.
“Some of them threw their empty bottles on the ground and there was one with his top off doing a lot of shouting.
“There must have been about 60 of them, but I think most of them were just following the crowd.”
A spokeswoman for Police Scotland said: “Tayside Division officers attended a disturbance involving a group of youths at Brown Street, Broughty Ferry, at 7.15pm on July 24.
“A 16-year-old boy was assaulted and he suffered minor injuries. He did not require medical attention.”
Meanwhile, the scattering of piles of litter including alcohol containers in Castle Green has sparked anger.
George Ferguson, chairman of the Broughty Ferry Community Council, said he was frustrated at the mess left in the park.
“People in general don’t seem to have the pride in their area they used to have,” he said.
“The rubbish they’re leaving behind could also be dangerous to the community, as there could be anything in it.
“I think people have to be educated not to drop their rubbish and just leave it.
“The only sort of solution I can think of would be to launch a campaign to keep the whole of Dundee tidy.
“There is an initiative in place to keep Broughty Ferry beach tidy, but I think that should be expanded.
“Unless there is a campaign put in place which people will recognise and respect, I feel nothing is going to make much of an impact to the littering problem.”
Anyone who witnessed the assault has been asked to call Police Scotland on 101.