A 21-year-old man has been detained by police in connection with the disappearance of missing nurse Karen Buckley, it is understood.
Miss Buckley, 24, has not been seen for almost four days and police divers, a helicopter crew and search dogs are all now involved in the search for her.
Police Scotland said they are now “following a definite line of enquiry”.
Teams have been scouring Dawsholm Park where her handbag was found yesterday and a nearby flat in Dorchester Avenue where the student was reportedly last seen.
Two officers in forensic suits entered the flat and an area to the rear of the block was taped off.
Officers later cordoned off land near High Craigton farm and Windyhills Golf Club on a country road between Glasgow and Drymen.
Yesterday, police appealed for information about a grey car spotted on the road between 11am and 3pm on Monday.
The detective leading the hunt for Miss Buckley has said it is his “absolute priority” to find her.
Detective Superintendent Jim Kerr said earlier: “We have a team of specialist search officers from the west and east working in the area as well as additional patrols in the west end and north of the city.”