Police in New Glasgow, Nova Scotia have expanded their search for 19-year-old Amber Kirwan, who disappeared early Sunday after spending the night at a pool hall with her friends.

Const. Ken MacDonald, a spokesman with New Glasgow Police, said a K9 unit was brought in to help with the search on Tuesday.

Police were seen scouring the grounds of the old Tibbetts Paint Factory on Glass Street in Trenton - not far from where Kirwan was last seen - on Tuesday. The building has been abandoned for more than 20 years.

"This building has been subject to vandalism, as a youth hangout," said MacDonald. ‘There's been some people broken into the fence, broken into the building itself, so as part of our investigation we called in our K9 unit to do a systematic search."

Kirwan was last seen by her friends around 1:30 a.m. Sunday, after she left Dooley's in New Glasgow. Her family reported her missing around 5 p.m. Sunday.

Kirwan's friends said she left Dooley's to meet her boyfriend at Big Al's, a nearby convenience store, but she never showed up.

Her boyfriend, Mason Campbell, told CTV News on Monday that he arrived to meet her at the store, but she wasn't there. He said he believes she is either lost, or that somebody is holding her against her will.

"She's not the type of person not to call either her parents or me or any of her friends," he said Monday.

Other family and friends have also said her disappearance is out of character.

Police and dozens of friends, family members, and community residents conducted a massive ground, air and water search Monday, but so far there has been no sign of the young woman.

The search had mainly been focused in New Glasgow, close to where she disappeared and along the East River, but police expanded their search today to include the outskirts of the town and into the neighbouring community of Trenton.

"Ground search and rescue teams don't conduct building searches, so that's why we use officers and our canine unit," explains MacDonald.

Some of Kirwan's friends expanded their search as they distributed posters around Halifax in the hopes that someone may come forward with information.

"I know if I was missing I wouldn't want my friends to give up," said Maggie Chickness, a close friend who was with Kirwan the night she disappeared. "I know what I'm going through, personally, for being one of the last people to see her. I can't even imagine what her parents are going through and I don't want to give up."

In Pictou County, many residents said the young woman's disappearance has struck a note of fear and concern, in what is usually a quiet community.

"I think it's just a really, really sad situation," said resident Jamie Hubley. "I don't even know the girl and it's just, it's really heartbreaking to know that it's going on around here."

"As each day goes by, I would say it's a little more scary," said resident Karen Gillis. "You know, your heart goes out to her parents. They must not be sleeping, worrying all the time."

As for the search effort, MacDonald said any evidence gathered by police today will be used to determine what form the search will take on Wednesday.

Friends said Kirwan was last seen wearing a blue and black shirt and flat, black shoes. She is roughly five-foot-one inches tall and weights around 130 pounds. Kirwan has brown hair and two tattoos – a dragonfly on her back, and a star on her right foot.

Anyone with information on her whereabouts has been asked to call New Glasgow Police or Crime Stoppers.

With files from CTV Atlantic's Dan MacIntosh