Police said they received information about the potential threat at 9 a.m. ET on Tuesday and the mall chose to close after managers were advised of the situation.
The nature of the threat or how it was received have not been disclosed.
Police spokesman Const. Pierre Bourdages said officers entered a Dartmouth residence on Everette Street, off Pleasant Street, in connection with the threat investigation, but found nothing or no one inside that would help the investigation.
Bourdages would not say what police were looking for, only that it was in connection with the mall threat.
"That investigation is ongoing. We are still trying to determine the validity of the threats that were made," he said.
According to Bourdages, officers are still on scene at both the mall and the home.
"There is no threat to anything else at this time. The information we received was about a specific potential threat against a specific area, a specific mall, which was Mic Mac Mall," he said.
Bourdages asked the media not to Tweet photos of specific officers at the scene investigating, saying it could jeopardize their safety or their lives.
"[We] ask you not to disclose specific locations where officers are, and that's for safety," he said.
The mall tweeted it would stay closed for the remainder of the day.
Crichton Park School, which is on Lyngby Avenue close to the Mic Mac Mall, was in a hold and secure mode because of the threat, the Halifax Regional School Board tweeted. South Woodside School, on Everette Street, was also in a hold and secure mode, the school board said. That was later lifted and both schools were dismissed at regular time.
Employees, customers told to leave
Jennifer MacLean, who works at a women's clothing store in the mall, said she heard an announcement on Tuesday morning asking everyone to leave the building immediately.
"Everyone came outside, and the police came out a couple of minutes later and just said the mall was closed for the day. No one was allowed back in," she told CBC News.
"People didn't even really know what was going on. There were still people wandering around. They hadn't heard it. There were still people coming in or trying to come in."
MacLean said she grabbed her store keys and jacket, locked up and went outside. She was told she couldn't go back in to get her purse.
She said the first thing that came to mind was the alleged mass shooting plot, foiled by police several weeks ago, that officers said was to happen at the Halifax Shopping Centre on Valentine's Day.
"It makes you think a little bit more about stuff like that," MacLean said.