A father from Norfolk has issued a heartfelt appeal to anyone who may have seen his son.
Pawel Martyniak, who's 21, was last seen on Tuesday (November 30) in the Carrell Road area of Gorleston. His family reported him missing in the early hours of Wednesday.
His father Andre described him as vulnerable - and said the family were very worried.
"We are very concerned about the welfare of Pawel as we feel he is very vulnerable and we want to make sure he is safe and well," he said.
"We are directly appealing to members of the public to come forward with any information or sightings they may have which could help to bring him home."
Norfolk Lowland Search and Rescue teams are carrying out searches in the area.
Police said Pawel likes to visit local woodland areas near his home - and that he may be "shy" or "confused" if approached.
He is described as white, approximately 5ft 10in and of medium build with brown curly hair and dark facial hair.
He was wearing grey Nike tracksuit bottoms, black adidas trainers, with a white sole and white stripes, white t-shirt and a brown/beige jacket with white fur collar.
Anyone with information is asked to contact Norfolk Police on 101, quoting incident number 9 of December 1.