Nine people have been killed in three related incidents in Edmonton in what police in the western Canadian city said was likely an act of domestic violence and the worst mass murder in nearly 60 years.

Eight people were killed, seven in one location and the eighth in another, police said, and a man linked to the crimes committed suicide in a nearby town.

Two of the victims were children while four women and two men were also dead in what Rod Knecht, the city's chief of police, called an act of domestic violence.

"This series of events are not believed to be random acts, and there is no risk to the broader public," Knecht said at a televised press conference. "These events do not appear to be gang related, but rather tragic incidents of domestic violence."

Police said the first victim, a woman, was found in a house in the city's southwest. Later in the evening they were called to another private home to check on a man who "seemed depressed and overly emotional," Knecht said.

The man was not found, however, and police returned to the house just after midnight to find seven bodies. Then, a vehicle linked to the crime was located 30 kilometres (19 miles) northeast of Edmonton, in Fort Saskatchewan, a town of 22,000, where the suspect killed himself in a restaurant, police said.

Mass killings are nearly unheard of in Edmonton, a city of 878,000 people which had 27 homicides in 2013. Knecht said the murders were the worst mass-killings in the city since at least 1956, when six people were murdered.

Edmonton is the capital of the province of Alberta, whose oil sands are the largest source of US crude oil imports.

In April, five people were stabbed to death in nearby Calgary, Alberta in that city's worst mass murder.

(dna)