A second man has been arrested on suspicion of murder in connection with a missing university student.
Thomas Jones, 18, from Bromsgrove has not been heard from since the early hours of Wednesday morning.
A 20-year-old from Worcester is in police custody along with another man, also aged 20.
Prior to the second arrest West Mercia Police shared CCTV images, of two men they wanted to speak to, recorded at nearby Velvet nightclub.
Mr Jones is still missing.
The force said it believed he had crossed the Sabrina footbridge, near Worcester Racecourse, and then walked on to the footpath that runs along the top of the flood defences on Hylton Road in the direction of Hallow, just before 03:50 BST.
Police said there had been an “unprecedented response” to the case, with hundreds of volunteers supporting the investigation.
Supt Damian Pettit said: “We are continuing the investigation with a number of lines of enquiry and will keep the community updated with developments in our continued investigation.
“Thomas’ family has been made aware of the updates and they are being supported by specially trained officers.”
As searches are ongoing, police have asked people to “kindly stay away” from the area to allow officers and divers to work “without distraction”.
The student was embarking on a primary teaching course at the University of Worcester and had only moved on 16 September.
His aunt, Jackie Rogers, said a “small army” was carrying out house-to-house inquires in and around Hylton Road and was determined to “find our boy”.
Mrs Rogers said the teenager sent a Facebook message to a friend at 03:46, but no-one had heard from him since.
Mr Jones was believed to have been wearing pale-coloured jeans, a navy blue, woollen zip-up Lacoste top and green shoes at the time of his disappearance.