Toronto police say they have arrested two teenagers after a security guard was shot at Yorkdale Shopping Centre at about 1 p.m. on Thursday.

Police say an 17-year-old and a 15-year-old got into an argument with a shopper in the mall's parking lot before heading inside. The shopper saw that one of the suspects had a gun.

Const. Tony Vella says the teens were then confronted by two security guards and a police officer inside the tunnel hallway where the subway meets the mall.

At some point during the altercation, a shot was fired at the security guard's chest, Vella says.

The victim was treated at the scene for minor injuries because he was wearing a bulletproof vest.

Police say the 15-year-old allegedly had a gun in his pocket and fired the shot.

Both teens were taken to the police station, where officers discovered that the 17-year-old had been shot in the leg. He has been taken to hospital and the Special Investigations Unit is trying to determine how the shooting occurred.  

A small caliber gun has been seized and a police perimeter set up at the scene of the shooting has reopened.