The province's police watchdog is now investigating after York Regional Police officers shot and killed an armed man who entered a bank in Vaughan, Ont. Wednesday and took more than a dozen hostages.

The Special Investigations Unit (SIU) is called in whenever someone is killed or injured during an interaction with the police.

York Regional Police Const. Andy Pattenden said police needed "lethal force" to gain control of the situation at an RBC bank branch located at the corner of Major Mackenzie Drive West and Dufferin Street.

Police responded to a call just after 1:09 p.m. about a man with a gun inside the bank.

Andy Pattenden

Const. Andy Pattenden said a motive has yet to be determined. (Sebastien St-Francois/CBC)

"When our officers did get there, as quickly as they could, they did in fact find a man inside the bank with a gun," said Pattenden, adding first responders were able to get many bank employees and patrons out.

"Unfortunately, they couldn't get everybody out, so it did turn into a hostage situation for us, and our emergency response team brought in negotiators," he said.

"Lethal force had to be used on the suspect in order to gain control."

vaughan mall hostage

Police responded to a call just after 1:00 p.m. about a man with a gun inside the bank. (Makda Ghebreslassie/CBC)

Pattenden said "there were no physical injuries," and a motive has yet to be determined.

"Two police officers discharged their firearms," SIU spokesperson Jason Gennaro said at a news conference later on Wednesday. "The man was struck and pronounced dead at the scene."

Gennaro said there was no indication the 25-year-old man, who lived in Vaughan, had fired his weapon.

He also said 13 hostages, both bank employees and customers, were taken during the ordeal.

dufferin major mack


'Get out immediately'

Mahen Arasaratnam, who operates the gas station near to the bank, said police told him to close down the station during the crisis.

"The police officer came to my front door and he says there's an armed robbery and a bomb threat, so vacate all the customers away, don't let anybody in, all the staff leave the place, close the business, get out immediately," he told CBC Toronto.

Arasaratnam said he complied with the requests, and later saw six to seven hostages being escorted by police to a bus. 

"They were so panicked, so upset," he said.

Magn Arasaratnam

Mahen Arasaratnam operates the gas station near to the bank and said police told him to close down the station during the crisis. (Sebastien St-Francois/CBC)

After the man was fatally shot, Gennaro said the bomb squad moved in and continues to the sweep the premises for explosives.

He said the SIU is expected to be on scene until at least into the early morning.

In a statement to CBC Toronto, RBC said: "Our number one priority is ensuring the safety and well-being of our clients and employees and we are extremely relieved that they are all safe and accounted for."

The intersection is closed and police are asking for drivers and pedestrians to avoid the area.