Trevor Hughes

USA TODAY

Las Vegas police are investigating a jewelry store robbery inside the Bellagio hotel-casino complex that sent frightened guests fleeing as masked suspects smashed glass windows with sledgehammers.

Police said three people wearing dress clothing — suits or tuxedoes — and animal masks smashed the windows, grabbed items from inside the store and fled.

“It is like a movie, it’s just crazy,” Las Vegas Metropolitan PD Lt. Carlos Hank told the Las Vegas Review-Journal.

One witness posted to Twitter a picture of a person wearing what appeared to be a pig mask and peering around a corner while standing beneath a Rolex sign. The witness, Twitter user Kir_Kamil, said the person in the pig mask tried to flee but was detained.

The incident happened shortly before 3 a.m. local time.

Police did not specify in which store the incident occurred, only that it was a high-end retailer. The Bellagio is home to several high-end jewelry and watch stores, including Tiffany, Tesorini, Omega and Harry Winston.

Witnesses originally reported hearing gunshots but police say it appears that was the sound of the glass breaking.

"Initial reports indicated there was an active shooter, however that proved to be false," police said in a statement.

Police said three suspects fled the robbery into the nearby parking garage and tried to escape in a vehicle. When it wouldn't start, they tried to carjack someone else's car, and then tried to run away, the Las Vegas Sun reported.

The Bellagio is home to an iconic water fountain show set to music that draws thousands of visitors an hour, especially during the heat of the day as shoppers browse the marble-floored shopping gallery.

Bellagio officials did not immediately respond to a request for comment.

Later on Saturday, police blocked the Las Vegas Strip after a suspect shot and killed one person and injured another on a two-story bus near the Cosmopolitan hotel.