A woman is facing charges after police responded to a report of a person carrying a firearm at the Halifax Central Library.

Halifax Regional Police were called to the library on Spring Garden Road just before 5 p.m. Sunday.

University student Michelle Rodriguez captured on video the moment her study session at the Halifax Central Library came to an abrupt end.

“We hear a girl over the PA system,” Rodriguez says. “She sounds very nervous, her tone is very nervous, almost sobbing at this point, and she says, everyone, please evacuate the library. And that's when all the alarms start going off.”

Rodriguez says she and her boyfriend didn't know where to go, so they went down the stairs out the fire exit to Spring Garden Road.

The firearm turned out to be a replica pistol -- not the real thing -- said Halifax police spokesman Const. John MacLeod.

Halifax Regional Police say some air guns and pellet guns are so detailed, it can be hard to tell the difference. Some are legal to own in Canada, but some are not. Police say it depends on their appearance and the speed at which they fire.

While some can be bought in Canada without a licence, police say they can still cause injury and can have unintended consequences.

“Until we can actually prove otherwise, we're gonna have to bring whatever resources we need,” MacLeod said. “We're gonna have to take whatever actions we would if this was indeed a firearm.”

That, MacLeod says, can put officers, the public, and the person in possession of the replica, at risk..

In the case of the replica seized at the Halifax Central Library, police say it has been sent away for testing to determine exactly which kind it is and to find out for sure if it's a prohibited weapon.

Two people were arrested at the scene without incident. No one was injured.

Caitlan Greenwell is facing charges of possession of a weapon dangerous to the public peace, and carrying a concealed weapon.

The 30-year-old Halifax woman was due to appear in court Monday.

A 25-year-old Halifax man has also been charged with public intoxication in connection with the incident.

A spokesperson for Halifax Public Libraries says staff members who were working Sunday were off Monday, and have been offered emotional support services through the employee assistance program.

When it comes to security, Halifax Public Libraries says it's “confident” in the measures it has in place, which includes security personnel on site.

With files from CTV Atlantic’s Heidi Petracek.