A schoolgirl is waiting to see whether she has contracted HIV after she was stabbed with a syringe.
The 16-year-old victim was with a group of friends on 30 March in Nottingham's Old Market Square where a live DJ event was taking place.
The teenager noticed a girl dancing in an erratic manner who approached her and stabbed her in the right thigh.
The victim has undergone tests and had injections to prevent diseases including hepatitis B and C.
A police spokesperson said: "This has been a significantly traumatic time for the victim and her family.
"They are still waiting to hear whether she has been given the all-clear.
"Incidents like this are rare but this was a mindless attack that has caused immense distress and worry.
"We need to catch the girl responsible and find out why she did this."
The offender is described as black, aged 14 to 15, 5ft to 5ft 3in (1.53m) tall and of slim build.
She had longish hair and was wearing a short red padded jacket which was fastened up at the front and had a hood with fur on it.