A Waterside councillor has warned that there could be protests if measures aren't taken straight away to stamp out drinking in St Columb's Park.
Scores of underage drinkers gathered in the park on Saturday night. An ambulance was called to assist one young person, while police monitored the scene.
There were no arrests.
The DUP's David Ramsey says he is very concerned the numbers involved in the outdoor gathering will escalate - as they did last year.
"The first good weather of the year, and the park is already overrun with drunken young people," he said.
"Up to 200 were witnessed by council wardens and the police could do very little because of the numbers. They did contain it and the park was cleared by 11.30pm.
"We are seeking an urgent meeting tomorrow [Monday] with the authorities. There is no way people in the surrounding area are going to tolerate this for another year. We have repeatedly said that this has to be dealt with early in the day before crowds gather and cause mayhem when alcohol is taken in a alcohol-free area.
"There will be protests arranged if this is not dealt with appropriately. The people living in the Waterside are sick sore and tired of this very important community space becoming a no-go area at night."
Alderman Ramsey said that alcohol must be seized from anyone attempting to bring it into the park.
And he expressed concern that there are not enough park wardens to cover the city in good weather.
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