The incident occurred in the Creevagh Heights area as officers conducted an ongoing policing operation. Police said some of the young people were masked and armed with weapons. Crowds dispersed at about 23:30 BST, and no injuries were reported.
Superintendent Claire Hamilton said an investigation has been launched and evidence gathered will be reviewed. She described the behaviour as "completely unacceptable" and said attacks on officers performing duties to protect the public are not welcomed by the wider community. Engagement with local representatives continues, she added.