Police have released an image of a man suspected of carrying out a series of needle attacks on women around Birmingham city centre.
West Midlands Police believe the man is responsible for a number of "strange" attacks which have occurred in the city over the past year and a half.
The most recent attack occurred on 3 November, when a 30-year-old woman felt a sharp pain in her right thigh which later turned out to be a puncture wound.
The offence is believed to be linked to similar attacks on a 20-year-old woman on 23 June and a 28-year-old woman on 6 October. Police believe all woman were stabbed with a hypodermic syringe.
Det insp Julie Woods, from Force CID, said: "We have received five reports in total over the last year-and-a-half and although the women have not been left with any obvious physical injuries they have had to endure an agonising wait to check that they have not suffered any long-lasting health effects.
"Whilst we have been unable to confirm exactly how the injuries were caused, it is believed that a hypodermic needle may have been used on each occasion, with young women being specifically targeted.
"Due to the nature of the offences, victims have not realised they have been injured until hours or days later, which has resulted in limited lines of enquiry. But we now have a particularly clear image of a man we want to identify in connection with the attacks and I would appeal for him, or anyone who knows who he may be, to come forward."
Police said they have stepped up patrols in Birmingham in a bid to reassure people visiting the city centre.
Supt Danny Long added: "This is an unusual offence which will understandably cause some concern and we are working extremely hard to find the person responsible."
Anyone who recognises the man in the image should contact detectives on 101 or call the independent charity Crimestoppers anonymously on 0800 555 111.