Northern Territory Police are calling for witnesses to an indecent assault incident in the Alice Springs CBD area on Monday afternoon.

Around 1.30pm, a female walking in a carpark on Railway Terrace was approached by a group of males, one of whom indecently assaulted her as he walked past.

The assault was witnessed by a member of the public who assisted the female to safety.

Police wish to speak to the person who assisted the female, and urge any other witnesses to contact them on 131 444 or report it anonymously via Crime Stoppers on 1800 333 000.

Motorists with dashcam who were travelling in the area of Railway Terrace/Coles car park around that time, are urged to contact police on 131 444 and reference PROMIS number 9983997.