Search for missing Sian O'Callaghan set to continue
The search for a woman who disappeared after leaving a Swindon nightclub is due to resume later.
Hundreds of volunteers joined police on Tuesday to search thousands of acres of woodland in the hunt for 22-year-old Sian O'Callaghan.
A signal from her mobile phone was picked up from Savernake Forest shortly after she left the Suju club to walk home at about 0250 GMT on Saturday.
The search of the forest near Marlborough is to resume at 1030 GMT.
A £20,000 reward to help find her has been offered by an anonymous donor.
Mobile records put her phone in the area of the 4,500-acre wood, 32 minutes after she left the club on what should have been a walk home of about half a mile (800m).
Police say the journey to the woods could only have been made by car.
Miss O'Callaghan's friends and her boyfriend Kevin Reape joined the search on Tuesday along with coachloads of local people, many of whom did not know the missing woman, after a police appeal for help.
Police have said people who wish to volunteer on Wednesday should gather at Postern Hill in Savernake Forest, wear suitable clothing and footwear and bring refreshments and a mobile phone.
They said people should sign in on arrival and be briefed on the operation and only search where they were told to.
Wiltshire Police said Miss O'Callaghan, who worked as an office administrator, had an LG E900 Optimus mobile phone and asked for anyone who finds one to contact the force.
A vigil and prayer service is due to be held for Miss O'Callaghan in Swindon during the evening.
The service at St Barnabas Church in Gorse Hill is to start at 1900 GMT.
'Out of character'
CCTV footage of Miss O'Callaghan alone in the nightclub has been released in the hope it will jog revellers' memories.
The black and white footage shows her walking downstairs and outside through the club's entrance, past a small group of men.
A police spokesman said the times shown on the CCTV were about six minutes slow.
He urged anyone who remembered seeing Miss O'Callaghan to contact the force.
Her disappearance has been described as totally out of character.
More than 60 police officers are working on the investigation which is being treated as a missing person inquiry.
Det Supt Steve Fulcher said: "Sian left Suju and walked along the High Street in Old Town and there were a number of vehicles moving through the High Street between 2.55am to 3am.
"We would like to identify the people in those vehicles as possible witnesses.
"I'd also like to hear from anyone who saw any vehicles in or near beauty spots between Swindon and Savernake between 3am and 4am.
"It is very important that people come forward as they may have vital information which will help us to find Sian."
At a news conference on Monday, her boyfriend, who shared a flat with Miss O'Callaghan, appealed for information to help find her.
A Wiltshire Police spokesman said Mr Reape was not being treated as a suspect.
Also present at the news conference were Miss O'Callaghan's parents Mick, 51, and Elaine, 48, brother Liam, 24, and sister Lora, 19.