Police are searching for a group of suspects they believe are responsible for a robbery at Casino Calgary early Wednesday morning.

Units were called to the scene shortly after 6 a.m., when they received a call from on-site security.

They say that security officials heard breaking glass in the building and then spotted suspicious individuals on security cameras removing an ATM.

No one was injured in the incident and police say that security teams did not make contact with the alleged thieves.

According to a casino manager, the thieves fled with an empty ATM.

Police originally believed that firearms were involved in the incident, but now think that the offenders were seen holding tools.

Investigators say they are looking for two or three people, all dressed in black. They fled the scene in a gold van.

Those in the area were surprised at what went on. "I saw it on the news this morning, so it's a little scary to think that people can break in and do this," says Jocelyn Gallais.

Colleen Farmer is a longtime resident in the area where Casino Calgary is located. "For the 16 years that I've been here, we've never had anything like this happen."

The investigation is ongoing.