Update 10.23pm: Lancashire police have released the following statement:
A missing girl has been found safe and well in Cumbria this evening (September 1).
Jessica Wallwork, 13, from Nelson, was found in Furness around 8.50pm.
Two men, aged 47 and 22, both from Nelson, were arrested at the scene on suspicion of child abduction.
Earlier: A search is under way for a 13-year-old girl who is believed to be in the company of a 47-year-old man, UK police said.
Dean Hughes, 47, of Temple Street, Nelson, is wanted by Lancashire Police on suspicion of child abduction after Jessica Wallwork disappeared four days ago.
The teenager was last seen on August 28 when she left an address in the town. She has not made contact with friends or family since and is not answering her phone.
Police say they believe she is in the company of Hughes and have serious concerns about her welfare. Pictures of them both have now been released by the force in a bid to track Hughes down.
Hughes and Jessica are thought to be in a black Vauxhall Insignia with the registration plate BN09 FDP. The vehicle was traced to Ulverston in Cumbria at approximately 3pm on Wednesday but has yet to be located.
Hughes is described as white, 5ft 6in, of medium build with short grey hair and brown eyes, and a soft North West accent.
People are advised not to approach Hughes and to contact police if he or anyone who matches his description are spotted.
Det chief inspector Jill Johnston said: "We are extremely concerned following Jessica's disappearance and are appealing for the public's help in finding her.
"Following extensive inquiries, we believe she is in the company of a man called Dean Hughes.
"Clearly Jessica is only 13 years old and we have serious concerns about her welfare, and would urge anyone with information as to her whereabouts to contact police immediately.
"Both we and Jessica's family are extremely concerned about her and we would ask anybody who knows where she might be to get in touch.
"Similarly we would urge Jessica, if she sees this appeal, to get in touch and let us know she is safe."
Jessica is described as white with shoulder-length, light brown hair.
She was last seen wearing a blue hooded top with 'LEC' on the front, light blue skinny jeans and a cream-coloured handbag. Police say it is possible she was wearing trainers.
Anyone with information should contact police on 101, quoting log number 955 of August 29.