A 20-year-old woman was grabbed from behind in Acton last night, by a man who pinned her against a wall and attempted to indecently assault her.

The attack follows two other indecent assaults in the Acton area over the last month involving a man matching a similar description, and has prompted a safety warning to the public by police.

Police say the woman was walking along Daley Road at about 9.40pm last night when a man grabbed her, restrained her using both arms and pushed her against a wall.

She managed to break free and ran away.

The man is Caucasian in appearance, in his late teens to early 20s, about 173cm tall, with an average build.

He was wearing a striped rugby jumper, grey tracksuit pants and a khaki, army-style flat hat.  

ACT Policing have warned that two other indecent assaults have taken place in the Acton area in the last month, and victims provided similar descriptions of their attacker to police.

The public has been asked to be cautious in the area and be aware of their safety.

Anyone with information who may know someone matching this description or have seen the attacks is asked to call Crime Stoppers on 1800 333 000, or go to the Crime Stoppers website.