The girl, who is in her late teens, was walking close to the entrance of Primrose Gardens, Banbridge, when she was approached by a man during the early hours of last Thursday morning.
Speaking to the Leader, two young women who live in the Primrose Gardens area, said that they now feared for their safety since the incident.
"I was heading to work when I saw that a police forensics team had set up a tent. I just couldn't believe it when I heard what had happened to the girl," said the teenager.
Her friend added, "I've walked up this road so many times after a night out, but I would be worried about doing that from now on."
Local councillors have condemned the incident and urged anyone with information to contact the police.
Councillor Junior McCrum said that the individual responsible for the sex attack "needed to be taken off the streets".
He added, "This is an appalling incident and my thoughts and prayers are with the victim and her family at this time."
Echoing Mr McCrum's comments, Councillor Joan Baird said that she had been left feeling "disgusted and saddened" by the incident.
"Any person, young or old, will have been left feeling concerned and vulnerable about their safety – unfortunately it's the age we live in," she explained.
Meanwhile, Sinn Fein councillor Dessie Ward offered messages of support to the victim and her family.
"This is a terrible incident which has harmed Banbridge's reputation," he said.
Police are appealing to anyone with information or who may have witnessed the incident, to contact detectives on 0845 600 8000. Alternatively information can be passed anonymously to the Crimestoppers charity on 0800 555 111.