Two people have been arrested in connection with a series of sexual assaults in Cardiff Getty Images

Police investigating three sexual assaults which occurred within a mile of each over a period of five days in Cardiff city centre have arrested a second man in connection with the initial incident.

South Wales Police are questioning a 40-year-old man on suspicion of sexual assault after a woman was attacked in the early hours of 20 September near the Cardiff University main building. Two days later a second woman was assaulted on Cathays Terrace followed by a third sexual assault at Gorsedd Gardens in Cardiff Civic Centre at 4.30am on 24 September.

Police have said it is still too early to speculate whether all three attacks were by the same suspect despite the similarities in terms of the locations, times and nature of the assaults. All three of the victims were aged between 19 and 20 and are believed to be students at Cardiff University. A 22 year old man from Cardiff who was previously arrested as part of the investigation remains in custody.

Head of Cardiff CID Detective Chief Inspector Richie Jones said: "We are treating these incidents extremely seriously and a full and through investigation is ongoing, involving a large number of officers from a range of specialist departments. We are doing everything possible to bring those responsible to justice and would appeal for anyone with information to contact South Wales Police."

Divisional Commander for Cardiff, Chief Superintendent Belinda Davies, added: "My message is one of zero-tolerance towards anyone who commits these appalling crimes – let me be clear that we will do everything we can to bring those responsible to justice.

"All reports of sexual assault are taken extremely seriously and South Wales Police, together with the Police and Crime Commissioner, have been working with partners to make tackling this type of crime a priority. Cardiff is a safe city and I want to keep it that way.

"As our investigation continues we want people to be able to go out, enjoy themselves and feel safe in our capital city. Crimes like this are never the victim's fault, but I would like to take this opportunity to remind everyone to follow basic safety advice so they keep themselves and their friends safe.

"Stay together when you're out at night, drink responsibly and make sure you all go home together. Always plan your journey home, book a reputable taxi firm, and if walking please keep to well-lit areas."

Cardiff University said it is helping detectives with the investigation into these "very serious incidents". A spokesperson added: "As part of our ongoing commitment to creating a safe environment for our students, our security team has been visiting student residences to discuss personal safety.

We're in consultation with our Students' Union and are discussing appropriate measures to help ensure our students' safety. We offer a range of professional support services to our students. We encourage anyone affected by these events to speak to someone in student support."