Police have released new CCTV stills of a man suspected of carrying out a string of sex attacks.
Five women have been sexually assaulted in a series of linked attacks in Canning Town, east London, in the last two years.
In the most recent sexual assault, which happened last Wednesday, a 25-year-old woman was returning home to her flat in Western Gateway near Royal Victoria Dock at around 11.30pm.
As she was waiting for the lift, a man, believed to be the one shown in the CCTV stills, grabbed her and sexually assaulted her.
He had short black hair and stubble, and was wearing a dark zip up coat and burgundy trousers.
Detective Constable Tina Dilworth said: "The man responsible for these assaults must be stopped before he goes on to commit another offence.
"If you recognise the man shown in these images, please contact my team immediately.
"Also, we would like to hear from any other women who live in this area who may have been assaulted by this man.
"I can understand why you may not have come forward, but if this has happened to you, you may have a vital piece of information that can help us stop him."
Detectives believe that the suspect may live or work in the area.
Ms Dilworth added: "His offences started back in 2011.
"I'd ask people to think if they know someone who travels and may have been out of the country during the gaps between these offences."
The first attack was on June 22 2011 at around 11:45pm when a 51-year-old woman was targeted as she returned to her apartment block in Seagull Lane.
A second attack happened on October 14 that year at around 8.30pm, when a 22-year-old woman was in a lift inside a block of flats in Western Gateway and was assaulted.
The man threatened to kill her if she told anyone, and sexually assaulted her for a second time as she tried to escape.
The third attack was on November 9 2012 when a 26-year-old woman was followed into flats in Seagull Lane at around 12:50am.
This year the suspect struck for a fourth time at flats in Seagull Lane on May 2, attacking a 28-year-old woman.
Anyone with information can call police on 020 8345 9862 or contact Crimestoppers anonymously on 0800 555 111.