Detectives are appealing for witnesses after an unknown substance was thrown in the face of a woman in Ipswich.
The incident occurred at around 7.15pm on Tuesday 13 September at the junction of Melville Road and Wellesley Road.
The victim, a woman aged in her early thirties, was walking her dog when she encountered a man who was leaning against the sign for Melville Road.
As she passed the man he threw a clear liquid from a bottle in her face, which caused reddening to the skin and slight swelling.
Hospital tests did not find evidence of any corrosive material being evident in the liquid, but further forensic tests will take place to try and determine what was in the bottle.
The suspect is described as black, approximately 5ft 11in tall, of skinny build, wearing a black hooded jacket (with the hood up), yellow t-shirt, dark blue jeans and sunglasses.
Any witnesses, or anyone with information about this incident, is asked to contact DC Olie Walker at Southern Area CID on 101 quoting reference 55330/16, or Crimestoppers anonymously on 0800 555 111.