Police in Dunedin are investigating two separate sexual attacks involving three women, on St Patrick's Day near the University of Otago.
Detective Senior Sergeant Kallum Croudis said the first Friday night attack took place at a house known as The Hospital, where two 19-year-old women were assaulted by a man about 8pm.
The police said he was wearing shorts and a T-shirt and had dark hair and dark skin.
Mr Croudis said another woman was sexually assaulted while walking on Leith Way about 9.30pm by a Caucasian man with long curly hair.
All three victims were traumatised and police were now examining local CCTV footage, he said.
The Otago Students Association said it was concerned to hear of two sexual assaults happening in student areas at the weekend.
"This seems to be quite serious in nature - and not that anything else isn't serious - but this seems to be at the upper end of the scale. The areas in which they happened, you'd kind of expect them to be students. That street is right inside the student area."