Two men have been charged and a third man is also in custody as detectives investigate the rape of four women in the past few weeks in Brighton.
Other sex attacks in the centre of Brighton and on the seafront have also been reported during the same timeframe, Sussex Police said.
The force said: “On Wednesday 6 September, police received a report that a young woman had been raped on the beach near the Palace Pier shortly after midnight.
“Three days later, on Friday 8 September, officers were called to London Road in the early hours after a report that a woman in her twenties had been sexually assaulted at around 3.15am.
“A man has subsequently been charged with rape and attempted rape, in relation to both incidents, and remanded in custody.”
Ahmed Lahmatar, 36, of no fixed address, is due to appear in court on Tuesday 10 October charged with rape and attempted rape.
Sussex Police said: “On Sunday 10 September, police were called to the beach near the King’s Road Arches at around 5.35am by a member of the public concerned for the welfare of a woman in her thirties.
“Officers arrested a man at the scene, who has been charged with rape and remanded in custody.
“Inquiries to trace a second suspect in the investigation are ongoing. Officers are keen to speak to the man captured in these CCTV images and are asking anyone who recognises him or has any information to get in touch.”
The investigation is known as Operation Carpenter.
Ali Mozaffari, 36, of Golders Green Road, in Barnet, is due to appear in court on Tuesday 10 October charged with rape.
Sussex Police said: “In the early hours of Saturday 16 September, police received a report that a woman in her twenties had been raped on the beach.
“Following inquiries, a 31-year-old man was arrested on suspicion of rape and being in possession of a class B drug – cannabis. He has been remanded in custody in relation to a separate matter.
“An investigation is also ongoing into reports of a woman being raped on the seafront near the Palace Pier and another sexually assaulted near by shortly after 3am on Sunday 24 September.
“Inquiries to locate the suspects are ongoing and anyone with information which could help police with their investigation are asked to come forward.
“Each of the victims is being supported by specialist officers while thorough investigations are carried out.”
Sussex Police also said: “Police have charged two men and arrested another following separate reports of rapes and sexual assaults on Brighton beach and in the city centre.
“Patrols have been stepped up in the area and the force is working with pubs, clubs and other venues to help people safely enjoy their nights out.
“The offences have been reported in the last three weeks around a similar geographic area.
“Two of the offences are linked as a single suspect has been charged and remanded, but there is no link between this and the other ongoing investigations.”
Detective Superintendent Richard McDonagh, head of Sussex Police’s Safeguarding Investigations Unit, said: “We understand the public will be concerned by these reports and we are offering specialist support to each of the victims in these cases.
“They are fast-moving investigations and we are grateful to all those who made reports and supported our inquiries, helping us to swiftly bring three suspects into custody.
“Women and girls should be able to enjoy a night out in safety. These incidents highlight the importance of targeting perpetrators, reducing their ability to cause harm and protecting people in vulnerable situations.
“We have extra officers carrying out extended patrols in the area, alongside the wide range of safety measures with our partners to keep people safe in the city centre.
“If you feel threatened or made uncomfortable by someone’s behaviour, please report it to security staff, a police officer or by dialling 999 in an emergency. The same applies if you see someone behaving suspiciously or who appears to be vulnerable.
“We would remind people of the ‘Ask for Angela’ scheme which allows anyone who feels unsafe, vulnerable or threatened to discreetly ask for help in the city’s venues.
“We would also encourage the public to download the Safe Space Sussex app which highlights the location of safe spaces where people can wait for a friend or taxi.”
Detective Superintendent McDonagh added: “In addition to extended patrols in the area, we are working with venues and partners – including night safety marshals, Beach Patrol, taxi marshals and Safe Space – to help keep people safe.
“Digital screens highlighting support services such as night safety marshals, who can escort people to safe locations and link in with officers via their mobile handsets, are also being displayed in venues across Brighton.
“If you have concerns or feel unsafe, please contact police or a member of security staff or dial 999 in an emergency.”