Searches for a missing 21-year-old University of Hull student are continuing after police said they are "extremely concerned" for her welfare.
Libby Squire has not been seen since disappearing late on Thursday night, and emergency services, as well as a group of fellow students and friends, have been searching for her.
Her family have said her disappearance is "very out of character", adding that she is "a very thoughtful and caring young woman who puts others before herself".
Superintendent Simon Gawthorpe said on Saturday: "Over 70 officers have been out searching speaking to her friends, visiting the pubs and clubs in the area and making inquiries with those who saw her during the evening.
"Despite these efforts, we still have not located Libby and as you can understand we are extremely concerned for her welfare."
Her friends and fellow Hull University also students spent Saturday looking for the 21-year-old in bitingly cold conditions.
More than 70 police officers were also out making inquiries, including knocking door-to-door around the area where the student vanished, in a bid to attain information.
Miss Squire was reported missing after getting into a taxi outside the Welly Club on Beverley Road, Hull, at around 11pm on Thursday, and is believed to have got out of the vehicle a short while later near her home address on Wellesley Avenue.
Humberside Police said she was then helped by a motorist who pulled over after spotting her on the street, with the force adding the man in question has since contacted them and has "really helped out" with the search.
Miss Squire was last spotted on CCTV on Beverley Road, near to the junction with Hayworth Street, at around 11.45pm on Thursday, the force added.
She is described as being 5ft 7in, with shoulder-length brown hair and was last seen wearing a black long-sleeved top, a leather jacket and a black denim skirt with lace.
On Saturday, officers could be seen scattered around the area where Miss Squire was last seen, and a group of students searched sports fields by the university in a bid to find their friend.
In a statement, the University of Hull said they are "deeply concerned" about the missing student.
A spokesman said: "Staff and students at the University of Hull are deeply concerned for the safety of student Libby Squire.
"We are working closely with Humberside Police to support their search for Libby and offering support to Libby's family at this distressing time."