Police are appealing for witnesses caught on CCTV on the night of missing Hull student Libby Squire's disappearance.
The 21-year-old went missing after a night out with friends more than two weeks ago.
She was last seen just after midnight on February 1 on Beverley Road, close to her home on Wellesley Avenue.
The footage shows four people on Oak Road close to the junction with Clough Road between 1.13am and 2.34am on February 1.
Police say they may be possible witnesses and have crucial information that could assist the investigation.
One man remains under investigation as inquiries continue.
Leading the investigation, Detective Superintendent Martin Smalley said: “While the footage isn’t clear enough for anyone to recognise who they may be, the four people in the clips will know if they were in that area at the times given and I would ask them to please come forward to assist with our enquiries.
“We have searched vast amounts of land around Oak Road including the playing fields as part of our enquiries, and the individuals in the footage appear to have been travelling from that general direction.
“The four people may have seen or heard something that could be vital to the investigation.
"If you believe you are one of them, or you know who they might be, please make contact with us on 101.”
The first clip shows an individual, believed to be in a light coloured T shirt and dark trousers, at first running into view on Oak Road and then walking out of shot at 1.13am.
The second clip shows a figure on a bike cycling along Oak Road towards Clough Road at 1.24am, and is then seen cycling back up Oak Road at 1.34am.
The third clip shows two people, one who appears to be dressed all in dark clothing and the second in light coloured trousers and a dark coloured top walking along Oak Road at 2.34am.
It comes as searches continue in and around Oak Road and also around the River Hull, with further work in connection to CCTV and witnesses.
The force said "field experts" were also working with them to ascertain exactly what happened that night and where Libby may be.
Det Supt Smalley said: “Libby’s family have been incredibly supportive of the investigation and my heartfelt thanks goes out to them as we relentlessly pursue every line of enquiry available, to give them the answers they desperately need."
He said the "is very much ongoing and active, with one man continuing to remain under investigation while we further our enquiries. "
If anyone believes they are shown in the clip or knows who they are they should call 101.