A mural in downtown Toronto honouring Canadian soldiers killed overseas has been defaced.

The Highway of Heroes mural is located at the end of the route taken by repatriated soldiers, in a back alley at a coroner's office near College and Yonge Streets. It marks the final stop for the hearses carrying the remains of Canada’s fallen soldiers.

More than 150 families have pulled into the alley next to the mural after their loved ones were killed overseas.

Using black and white paint, vandals spray-painted over the mural that once featured an image of an outstretched dove and a field of poppies.

Chris Ecklund, of Canadian Heroes, said the vandalism was an “act of treason.”

“This is one of the most important murals in Canada, and for somebody to come along and destroy this, it’s hard to understand,” he said.

Ecklund said veterans and the general public are outraged that vandals defaced the mural, which was only completed about a month ago.

Toronto Const. Scott Mills was the driving force behind the mural.

Mills -- who runs a legal graffiti program -- convinced local graffiti artists Kedre Brown and Jessey Pacho to create the mural three years ago. He discovered the vandalism on Friday.

“It pretty much moved me to tears,” he said. “I just can’t believe that somebody did something like this to such an iconic piece.”

Many posted comments on social media were outraged over the vandalism.

"SAD, SAD, SAD, … no respect … heartbreaking," one woman said in a post on the Canadian Heroes Facebook page.

Others hoped those responsible would be caught.

"This just turns my stomach! I hope they can ID this mess thru the style and nail these punks," another wrote.

The defacement is believed to have occurred sometime before Friday night.

With a report from CTV Toronto’s Zuraidah Alman