The search continues for a pack of men who gang raped a 14-year-old schoolgirl in what police described as one of the most ''horrendous'' sexual assaults in recent years.

Police said the victim had told them she was walking home from a friend's house when she was ''physically overpowered'' and raped by six men in a dimly lit park at Doonside, in Sydney's west, on Saturday night.

Despite her attempts to struggle free, one man pinned her to the ground of a pathway in Bill Colbourne Reserve and raped her before standing aside and allowing five other men to sexually assault her about 11pm, police said.

The attack was completely random and lasted about 30 minutes, police said.