Police are concerned about a woman who was seen barefoot in woodland near Lancing this afternoon.
A woman was seen around 3pm near to the dew pond at Lancing Ring and was stopped by a dog walker as she appeared to be distressed, police said.
However she would not stop and carried on walking, according to police.
The dog walker was concerned as she was walking away from the nearest house and appeared to be barefoot, police said.
She is described as white, in her 20s with short black hair, about 5ft 6ins, wearing just 3/4 length trousers and a grey sleeveless top which could have been pyjamas, police said.
Inspector Dan Russell said: "We have been making checks and searching the area during the afternoon and have found no-one, or had anyone reported missing, who matches this description.
"Do you recognise her or have you seen her this afternoon?
"We are very concerned about her welfare."
Anyone who can help should call police on 101 or 999, or report online quoting serial 691 of 05/03.