Two teenagers suffered burns to the face in an horrific spray attack.
The man and woman, both 18, needed hospital treatment after the incident.
Police revealed today that they were attacked in an alleyway from Stakes Hill Road to Purbrook Way - between Oaklands and Crookhorn Schools - sometime between 6.30pm and 7pm on Tuesday, June 26.
The couple were walking through the alleyway and approximately 90 yards from the junction with Purbrook Way they were approached by another teenage boy and girl riding a bike, who were coming from the opposite direction.
As they passed the teenage boy sprayed the man in the face with an unknown substance, and some of the spray also went into the woman’s face.
A police spokeswoman said that both victims experienced a burning sensation and their skin reddened and peeled.
Both needed treatment at Queen Alexandra Hospital in Cosham.
Detectives say the attacker is described as white,17-18 years old, between 5ft 8ins to 5ft 11ins tall, of medium build with short dark hair and spots on his cheeks.
He was wearing a dark coloured hooded top and blue denim jeans with faded patches on the knees
The girl with him is described as white, slightly younger than the offender and with short bleached light blonde hair in a messy boy’s style.
She was wearing a dark coloured hooded top and distinctive heavy black eye make up, described as Egyptian style.
Det Con Pete Budgen said: ‘This type of assault is thankfully rare. It was a mindless and unprovoked incident. The couple who sprayed the substance may have thought it was a joke, however the consequences could have been more serious.
‘The victims are now recovering at home but are left shocked by what happened and concerned about going out.
‘We are keen to speak to another young couple who where also walking in the alleyway around the time of the assault, they may hold vital information.’
Anyone with information should contact DC Budgen at Waterlooville police station on 101. Mini-Com users can call the police on 01962 875000. Information can be given anonymously by calling the Crimestoppers charity on 0800 555 111.