The woman was in Pelican Waters Nature Reserve off Tweddel Drive about 4.30pm when she saw a man sitting on a black pushbike.

She kept walking before the man walked up behind her and grabbed her arm, police said.

The woman turned and punched him, and was then punched in the face. She broke free from the man's grip and ran into the bushland.

Hiding in scrub, the woman made a phone call for help while the man called out to her before leaving the area.

Police said the man was described as aged in his late 20s to early 30s, about 175cm tall with a medium build and possibly a European or Middle Eastern complexion, with dark, curly hair cut short at the back and sides.

Police were appealing for anyone who may have noticed anyone suspicious in the area to contact them.