No wall of silence on rape: police

Police investigating the gang rape of a 14-year-old Sydney girl have taken the step of releasing security images of three men sought over the attack.

Detectives say the trio, all believed to be in their late teens or early 20s, were caught on CCTV cameras at Blacktown and then Parramatta railway stations on the night of the assault, in a Doonside park early last month.

It is alleged one man forced the girl to the ground and sexually assaulted her before up to five of his friends took turns during the following half hour.

A 16-year-old boy who went to a Sydney police station a week after the February 8 attack, has been charged with aggravated sexual assault.

Detective Inspector Mick Haddow from the State Crime Command's Sex Crimes Squad says the public has provided solid information on the case but almost a month on, investigators have decided to identify the suspects in the hope of a breakthrough.

"We are getting an enormous amount of assistance from the community," Insp Haddow told reporters on Tuesday.

However, the images, which were taken a short time after the attack, could prove vital.

"We can confirm those three males were travelling together on that night," he said.

Detectives don't know how the men know each other, and Det Insp Haddow couldn't say what assistance the 16-year-old charged over the attack has offered.

The incident sparked reprisal fears and calls for calm from African and Pacific Islander community leaders and police who took part in a unity walk through Blacktown.

The victim is a Pacific Islander, while all the alleged offenders have been described as African in appearance.

Insp Haddow said the 14-year-old girl and her family were in almost daily contact with detectives.

"The victim is doing very well, considering the ordeal she's been through," he said.

The 16-year-old accused is due in court next month.