THE major search for missing Karen Buckley intensified today as police detained a young man in connection with her disappearance.

Fears are continuing to grow for the nurse who was last seen more than four days ago.

Dozens of extra police officers have been drafted in as detectives vow to solve one of Scotland's most mysterious missing person investigations.

Karen, who is originally from Cork but moved to Glasgow to study for her master's degree, left a nightclub in the early hours of Sunday morning.

She has not been seen since.

Shortly before 7pm yesterday, it was revealed 21-year-old Alexander Pacteau was detained in connection with the disappearance.

Officers are also understood to be following a "definite line of inquiry".

Underwater divers and sniffer dogs were among the specialist units continuing the search today across Glasgow and Milngavie.

Rows of police officers combed a farm and secluded lane in Milngavie, while divers searched the River Kelvin, near to where Karen's black handbag was found.

Police maintained a massive presence, examining the rooms and garden of Mr Pacteau's flat in the West End of the city as officers searched for clues.

Last night, the focus of the investigation shifted more than six miles away to farmland in Milngavie, and the police helicopter circled between the village and Drymen.

Police activity has centred on four locations; Dawsholm Park, where the black handbag was found, a flat in Dorchester Avenue, an area of land near High Craigton Farm and a secluded lane near Windyhill Golf Club, Milngavie.

Detectives previously said they looking for a grey or silver car that was seen in the Milganvie and Drymen areas on Monday between 11am and 3pm.

Police today remained tight-lipped about whether the vehicle had been traced.

At Mr Pacteau's property in Dorchester Avenue, under the gaze of photographers and television cameras, forensic officers searched the communal front and rear gardens of the flat.

Officers dressed in protective white suits spent hours looking inside nearby garages and examining - and bagging - the contents of bins.

The exhaustive search also continued in the street, with rows of black-clad officers, examining gardens across from the sealed off flat.

Karen left The Sanctuary nightclub in the early hours of Sunday morning after telling friends she was going to the toilet.

She also left without collecting her coat.

Her pals said she had been drinking but was not drunk.

Security cameras captured Karen speaking to a man in Dumbarton Road, before getting into a car.

Meanwhile, a search of Dawsholm Park continued last night, with dozens of officers from across Glasgow, drafted in to help find Karen.

Her handbag was found in a bin near the park, which is not far from where she was last seen at 4am on Sunday.

After the discovery, police said they were "gravely concerned" about her safety.

Detective Superintendent Jim Kerr said: "Our absolute priority is to find Karen Buckley.

"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.

"Anyone with any information, no matter how insignificant it may seem, should contact 101 or anonymously on Crimestoppers."

Karen, who is brunette and 5ft 2in, was wearing a black jumpsuit and red heels when she was last seen.

Her shattered family arrived in Glasgow from Ireland on Monday.

Her mother Marion said: "We just want Karen home safely, we are desperate.

"She is our only daughter, we love her dearly."