A lone woman fought of a stranger who attacked her in a park and tried to choke her with a metal chain, police have said.
Detectives are now hunting for a man believe may have been involved in the "terrifying attack" in a park in east London.
Officers have released an e-fit of the suspect and are appealing for information.
The woman, in her 20s, was sat on a bench at approximately 11:30am on Friday, 10 September in Ingrebourne Valley in Hornchurch Country Park.
A Metropolitan Police spokesperson said: "It was reported that she was sitting on a bench when he came up from behind and placed a metal chain around her neck.
"The victim was able to free herself and ran out of the park.
"The suspect is described as being a black man, who was dressed in dark clothing and wearing smart pointed shoes.
"It is thought he had slicked-back black hair, with a silver streak."
PC Andy Tyler, from the local policing team in Havering, said: "This was a terrifying attack on a lone woman and I know it will cause concern among the wider community.
"We have increased patrols in the area since the incident and I can assure you that we are doing all we can to track down the man responsible."
