A 39-year-old man is in the intensive care unit at Dunedin Hospital with fractures to his skull, neck and possibly his spine after he was "brutally" attacked in a quiet residential area of the city yesterday morning.
It is one of four serious assaults at the weekend - two in Dunedin and two in Invercargill - being investigated by police.
Acting Senior Sergeant Nathan White, of Dunedin, said the victim was in a critical condition last night, after he was allegedly assaulted by a 31-year-old Dunedin man on Rawhiti St, in Musselburgh, about 6am.
Acting Sen Sgt White said the victim was on the street when he was allegedly punched and stomped on. Police believe the two are known to each other, but it is unclear what sparked the assault.
"It's a particularly brutal assault." The 31-year-old man was taken into custody yesterday. Police expected to lay charges this morning when the victim's condition had been reassessed, Acting Sen Sgt White said.
Anyone who witnessed the incident was encouraged to contact Dunedin police.
Police were also investigating the sexual assault of a 19-year-old woman on Montgomery Ave, near the University of Otago, yesterday morning.
Detective Sergeant Dave Nelson said the woman was walking from the central city to her home in north Dunedin, and while walking along Albany St she noticed a man acting suspiciously in a red vehicle.
"This vehicle has made two approaches towards the female.
The vehicle was last seen on Albany St," he said.
The woman continued to walk through the university area into Montgomery Ave where she was grabbed from behind.
Det Sgt Nelson said she was sexually assaulted between 3am and 3.30am by a male offender in Montgomery Ave near the intersection with Dundas St. The offender then ran off.
Police described the offender as having a strong Pacific Island accent, about 176cm tall, with a moustache, and of large build.
"A number of people are believed to have been walking in the university campus area around this time and police would like to hear from anyone in the area at the time, or who may have seen a male or red car, acting suspiciously," Det Sgt Nelson said.
Police are also investigating two serious assaults in Invercargill at the weekend.
Senior Sergeant MaggieWindle, of Invercargill, said a 36-year-old man was stabbed in the head several times allegedly during an altercation at an Earn St house, leaving him with head injuries.
The incident happened about 9am yesterday.
The victim was treated at Southland Hospital and later discharged.
A 24-year-old man, known to the victim, would appear in Invercargill District Court today facing assault-related charges.
Police were also investigating a serious assault in Nelson St, early yesterday in which a female and two males were injured following an altercation with another man.
Snr Sgt Windle said a variety of weapons were allegedly used during the assault, leaving one of the men with serious facial injuries.
He was taken to Southland Hospital in a serious condition while the other two required minor treatment.
A 50-year-old Invercargill man is in police custody but no charges have been laid, she said.