A gunman disguised as a policeman killed at least 18 people, including a female Royal Canadian Mounted Police (RCMP) officer, in what has been described as the worst mass shooting in Canada's modern history.
The victims included a teacher, a nurse, a police officer and a married couple.
The Royal Canadian Mounted Police (RCMP) revised the death toll of Sunday’s shooting in Nova Scotia, but warned that there could still be more victims from the rampage, which lasted for at least 12 hours and ended with a car chase.
Police said the suspect shot people at different locations in Nova Scotia, many of them randomly. He was killed in a confrontation with police.
Canadian president Justin Trudeau called on Canadians to stand unified in the face of “senseless violence”.
“No one man’s action can build a wall between us and a better day, no matter how evil, how thoughtless or how destructive,” the prime minister said on Monday morning.
"Violence of any kind has no place in Canada. We stand with you and we grieve with you," he said.
Gabriel Wortman was reported to have been driving in what looked like a police car.
Nova Scotia Premier Stephen McNeil told reporters this was "one of the most senseless acts of violence in our province's history".
RCMP officers continued pursuing Mr Wortman for hours, following a series of crime scenes that police said were "scattered across the province" and which they are still working to piece together.
Mr Wortman was later seen in the Glenholme and Debert areas, east of Portapique, driving what appeared to be a police vehicle and possibly wearing the uniform.
With Nova Scotia already in lockdown in order to contain the spread of coronavirus, Trudeau acknowledged the grieving process would be especially difficult, announcing a virtual Facebook vigil on Friday at 7pm.
Mass shootings are relatively rare in Canada where gun ownership laws are stricter than in the neighbouring United States.
Last year, two fugitive teenagers confessed to killing three people, including an Australian-US couple on holiday, in northern British Columbia.
The massacre in Nova Scotia is the worst of its kind in Canadian history, eclipsing the 1989 École Polytechnique massacre, in which 15 women were killed in Montreal. In 2017, a man killed six people at an Islamic cultural centre in Quebec City.