Protecting the public is a top priority for authorities, and with hundreds of large events hosted in Vancouver each year, securing them is becoming more challenging.

Over the weekend, there were two violent attacks that occurred near public events.

Five people, including a police officer, were injured in a chain of violent incidents that began outside an Edmonton Eskimos game on Saturday.

A little more than 24 hours later, a shooter opened fire on a crowd of country music fans in Las Vegas, leaving 59 dead and at least 527 in need of hospitalization.

Following the events, CTV News went to officials in Vancouver to find out what's being done behind the scenes to keep local residents and visitors safe in the event of a similar attack.

Sports fans are required to go through airport-style metal detectors to attend all major sporting events, and heavily armed officers were seen keeping an eye on Canada Day crowds.

Even Remembrance Day last year was guarded by police with assault rifles on the ground and on nearby rooftops.

Ashley Meehan of Genesis Security, told CTV that securing large events has drastically changed in the last five years.

"They're blocking off roads now with larger trucks or police vehicles for the parades and those sorts of things," Meehan said.

"Even the uniforms that they have and the tactical teams coming in, we've seen a change with that."

But some public spaces around BC Place and Rogers Arena, surrounded by highrises, are vulnerable to attacks from above, and attacks could happen anywhere.

"It could be in Vancouver, it could be in Victoria. There's no particular place they're interested in," said Simon Fraser University terrorism expert Andre Gerolymatos.

"All they want is publicity. They want the body count and for it to be in the news."

While police won't provide specific details on their tactics, Gerolymatos said it's almost impossible for law enforcement officials to prepare.

"When you figure out one way to protect the stadium, they move into a shopping mall. When you do a shopping mall, they move into a schoolyard."

Although the location may change, behaviour does not, Meehan said.

"Some of the key things that we look for would be some sort of suspicious behaviour, how they're dressed. If it was a warm day, they're wearing heavy jackets, that would be suspicious," he said.

And experts said anyone concerned that something may happen can be proactive, looking for exits when they arrive at a venue and planning different escape routes should an incident occur. Groups can set up a meeting place a few blocks from the venue in case of emergency.

In the event of a mass shooting or other attack, experts advise that the public be alert, try to listen to where the danger is coming from and find a place of refuge if possible.

B.C. RCMP said Sunday that members of the public may notice a heightened police presence in major cities, though they were not aware of specific threats to the province. The day after the Edmonton attack, Sgt. Annie Linteau said police will "exercise increased vigilance."

And the Vancouver Police Department said their department is in regular communication with other local, national and international police agencies.

"Vancouver is a safe place to live, work and visit," Const. Jason Doucette said in an email to CTV Vancouver. "As always, we continue to ask the public to remain vigilant and encourage them to report suspicious behaviour to police."

With a report from CTV Vancouver's Nafeesa Karim