An armoured truck guard is in hospital in critical, but stable, condition hours after police say he was shot multiple times during an ambush outside a Toronto bank on Thursday morning.

Toronto police say the 37-year-old guard — one of two operating the armoured truck owned by the company Garda World — was ambushed just after 1 a.m. ET as he got out to make a delivery to the TD Bank at 1677 Avenue Rd., just north of Lawrence Avenue West, in the city's north end.

Staff Insp. Mike Earl of the holdup squad told CBC News that the guard was "literally ambushed" on Thursday morning.

"It immediately ended up in an exchange of gunfire between the guard and the suspects. The suspects fired several shots at the guard and the guard returned fire.

"It was more of an ambush than a robbery."

Police said the Garda World employee was hit by four rounds. He was rushed to Sunnybrook Hospital in critical condition and underwent emergency surgery.

The other Garda employee who was driving the truck was not hurt.

The would-be robbers fled the scene, but three suspects were soon arrested in the nearby Lawrence Heights neighbourhood, where police said they reside. A handgun was also recovered.

Jaden Beckford, Rashid Clarke and Nicholas Cross, all aged 18, each face more than a dozen charges, including attempted murder, armed robbery, conspiracy to commit an indictable offence, and using a firearm during the commission of an indictable offence.

Police believe the same men attempted to rob a Garda World armoured truck two weeks ago, in the Bathurst Street and Lawrence Avenue West area.

The men appeared in court on Thursday.

"We are not looking for any other suspects in this incident," said Earl.

Witness heard shots, thought tire 'popped'

Police said multiple shots were fired, by both the guard and the men who ambushed him. Bullets struck buildings across the street and were found embedded in nearby utility poles.

Witness Pia Stein heard the gunshots and called 911.

"I just heard a couple of gunshots," she told CBC News. "First three gunshots and I thought maybe a tire popped, then I heard like five shots right afterwards. I got up and I saw a man lying on a sidewalk by the bank, and I saw movements in the money truck, so I called 911. My hands were shaking."

Police said no cash was taken in the robbery attempt. They are asking people in the neighbourhood who spot anything suspicious, such as discarded weapons or clothing, to contact them.

Unifor, a union that represents some 2,000 members in the armoured truck and secure logistics industry, called for regulatory changes to prevent similar incidents.

The union is calling for higher standards in training and a three-person crew on high-risk jobs such as stops at bank machines.

"This is a tragedy and these people will never be the same," said Mike Armstrong, a national representative for Unifor, in an interview with CBC News.

"Their families are going to suffer because these people were hurt at work. Nobody goes to work to get injured, let alone to get shot at, so our hearts go out to the families of these workers."

According to Unifor, there have been more than 70 attacks on armoured trucks in Canada since 2000.

The violence on Thursday comes just months after another incident at Toronto’s Fairview Mall in which an armoured truck was targeted in a robbery and gunfire was exchanged.  Almost five months after that January incident, police announced arrests in that case.

Canada has also seen at least one deadly incident involving an armoured truck in recent memory, a triple homicide that occurred in Edmonton two years ago.

With files from the CBC's Stephanie Matteis, Tony Smyth and Linda Ward