A teenager was taken to hospital with a fractured skull after being attacked by a group of four men with a wooden broom.
The victim, 18, and a woman, 17, were injured in the attack on the city’s Arklay Street, which happened at about 2.45pm on Sunday.
They were taken to Ninewells with the man suffering a fracture to his temple.
The pair’s attackers are believed to be aged between 18 and 20.
The mum of the 18-year-old said: “He is currently in the fracture unit at Ninewells Hospital and hopefully he is getting out today.
“If it hadn’t been for the help of passers-by I don’t know if he’d be here today as he was unconscious until the ambulance and police arrived.
“I’m devastated this has happened as he is such a quiet laddie. He has a fracture just above his temple and hopefully he’ll be out today.”
Police launched an appeal for witnesses of the assault.
A Police Scotland spokesman said: “We are appealing for witnesses after four men assaulted a man and a woman in Arklay Street, Dundee, at about 2.45pm Sunday.
“The suspects are described as being 18 to 20 years old.
“One of them is of slim build with short dark hair and was wearing a black t-shirt with a white logo and grey Nike tracksuit bottoms.
“Another of the men was about 6ft tall, of slim build with short dark hair and was wearing a grey Nike zip-up hooded top. The other two males were both of slim build with
short dark hair.
“The victims, aged 18 and 17, both sustained injuries to the head and body and were taken to Ninewells Hospital for treatment.
“Anyone with information in connection with the incident is asked to contact Police Scotland on 101.”
Resident Scott McKenzie, 48, said: “We’d been up at the shops at the time. There were three police cars and an ambulance at the scene. They were there for about 20 minutes. It was actually quite quiet at the time. The police were sitting in their car and I didn’t see anyone come out of the ambulance.”
Another eyewitness said: “I was driving up Arklay Street and there were lots of police cars and an ambulance. A police officer came to my door and I asked him what had happened.”