South Australian police have released a computer-generated image of a man suspected of sexually assaulting a 10-year-old girl in the public toilets of an Adelaide park last week.

Key points: A girl was sexually assaulted at Blair Athol last week

A girl was sexually assaulted at Blair Athol last week Police have released an image of the suspect

Police have released an image of the suspect He has been described as an Afghan male, aged 30 to 50

Last Wednesday, police were called to a community sportsground in Blair Athol after reports a man had sexually assaulted a child in the public toilets.

Special crime detectives investigating the assault have released an image of the suspect, who is described as an Afghan male, aged between 30 to 50, with a dark fringe that partially covered his forehead.

He was believed to be wearing a grey T-shirt, peach-coloured shorts and was in the company of two young girls believed to be between 3 and 5 years old.

Police at Blair Athol Reserve in Adelaide where a girl was assaulted on April 3, 2019. ( ABC News: Sarah Mullins )

Police believe other people were in the vicinity of the reserve at the time of the assault and they might have witnessed something unusual or a person acting suspiciously.

Police have also recorded a message in Hazaragi and Dari to appeal directly to anyone in the Afghan community who might be able to assist in the matter.

Man lured young girl to toilet block

Last week, Detective Chief Inspector Richard Lambert said the girl was confronted by the man before he enticed her into the toilet block.

"He then lured her into the toilets and sexually assaulted the young girl," he said.

"At the end of the assault the girl managed to break free and run away."

Police called on anyone who might have seen something to report it to Crime Stoppers.

"The fact that it was 6:00pm, there was soccer practice going on, there were significant people [around]," he said.

"I'd feel reasonably confident that people would have seen this person, particularly with two young children."

He said the girl was on the playground alone at the time and returned home after the assault, before being examined in hospital.

"It's difficult to tell the long-term impact, but the short-term impact, our impression is that she's a very articulate girl and strong-minded … at the moment she appears to be okay, but it's only early stages," he said.

Kilburn Football and Cricket Club president Dale Agius said in the past the club had expressed concern about "some of the dark spots" around the reserve.

In a statement, the City of Port Adelaide Enfield said the football club had applied for permission to install CCTV in 2013 and the council had granted it permission to install it at its own cost.

"The council has upgraded lighting around the Blair Athol Oval and car park area, and we continue to work with local community groups, police and other agencies in regards to public safety," Mayor Claire Boan said.