Dunedin police are on the hunt for a man who attacked a female jogger and slashed her face with a broken bottle.

The 18-year-old student was jogging through Jubilee Park at 11.30pm on Monday night when she fell or was tripped by her attacker, the Otago Daily Times reported.

The man assaulted her and attempted to rip off her shorts, Detective Dave Checketts of Dunedin police said.

She fought him off and he cut her face with a broken bottle. He eventually ran off.

The man, described as Caucasian, in his mid to late 20s, with short dark hair, was wearing a dark-coloured nylon windbreaker and possibly jeans.

The woman had a deep wound to her forearm and required stitches to cuts to her forehead and cheeks, Mr Checketts said.

"It was pretty ugly. This was no run-of-the-mill assault," he said.