A gang forced a young woman into a van at a town centre car park before driving away.
Police said the woman was approached by a number of men at Crawley Leisure park at about 9.10pm on Wednesday September 20.
The men got out of a white van and picked up the woman before putting her in the vehicle and driving off in the direction of Ifield Avenue.
Detective Sergeant Dave Morton said: “We had one call about the incident and we are appealing to anyone else who was at the leisure park who might have seen something which could help us work out what happened.
“We haven’t had any reports of someone missing. The woman is described as white, between 16 and 18 years-old and slim. She had shoulder length dark hair which was down and was wearing a pink vest top and black trousers.
“We are concerned for the welfare of the woman and anyone who witnessed anything or has any information should contact us online quoting serial 1323 of 20/09.”