Sixteen people, one of them a police officer, have been killed in the Canadian province of Nova Scotia after a gunman dressed as a police officer went on the country's deadliest rampage.

Key points: Police say there may be more bodies in a number of burnt buildings across Nova Scotia

Police say there may be more bodies in a number of burnt buildings across Nova Scotia The 51-year-old suspect was a local dental worker

The 51-year-old suspect was a local dental worker Police say the victims seem "very random in nature"

Gabriel Wortman, a 51-year-old dental worker, died after being arrested.

Police said he was at one point dressed as a member of the Royal Canadian Mounted Police (RCMP) and was driving a fake police car.

Constable Heidi Stevenson, a mother of two and 23-year RCMP veteran, was killed in the incident and a male officer was in hospital with non-lethal injuries, RCMP Chief Superintendent Chris Leather told reporters.

Constable Heidi Stevenson served with the Royal Canadian Mounted Police for 23 years. ( Supplied: Royal Canadian Mounted Police )

The incident began in the small coastal town of Portapique in Canada's east on Saturday night (local time), police said, where frightened residents took cover in their basements as officers responded to what was initially called a firearms complaint.

There were also numerous buildings burned and Chief Superintendent Leather said there may be more bodies in burnt buildings across the province.

He said the victims seemed "very random in nature" and that the suspect was not known to police and had no known history of violence.

Canadian police say Gabriel Wortman dressed in a police uniform and drove a fake police car. ( Supplied: Royal Canadian Mounted Police )

"We believe it to be one person who is responsible for all the killings and that he alone moved across the northern part of the province and committed what appears to be several homicides," Chief Superintendent Leather said.

He said the use of a fake police vehicle and uniform pointed to premeditation.

The fake police car was involved in a crash about 80 kilometres south of Portapique at Shubenacadie, where police said he moved to a silver Chevy SUV.

'We heard gunshots'

One woman said she came across two burning police vehicles while out driving on Sunday morning.

"There was one officer we could see on scene and then all of a sudden he went running toward one of the burning vehicles," Darcy Sack told the CBC.

"We heard gunshots," she said, adding one police officer appeared to have been injured.

The fake police car was involved in a crash in Shubenacadie. ( Reuters: John Morris )

Mr Wortman was arrested at the Irving Big Stop petrol station in Enfield, Nova Scotia, about 32 kilometres north of downtown Halifax and 92 kilometres south of Portapique.

Witnesses saw a body lying at the petrol station but police did not immediately comment on the identity.

Mr Wortman was listed as a dental prosthetist in the area.

A body is removed from a service station in Enfield, Nova Scotia. ( AP: The Canadian Press/Andrew Vaughan )

Canadian Prime Minister Justin Trudeau made a short statement about the incident on Sunday.

"My heart goes out to everyone affected in what is a terrible situation," Mr Trudeau said.

Portapique local Christine Mills said it had been a frightening night for the small town, with armed officers patrolling the streets. In the morning, helicopters flew overhead searching for the suspect.

"It's nerve-wracking because you don't know if somebody has lost their mind and is going to beat in your front door," Ms Mills said.

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Tom Taggart, an MP in the municipality of Colchester, 30 minutes east of Portapique, said the quiet community had been shaken.

"This is just an absolutely wonderful, peaceful, quiet community and the idea that this could happen in our community is unbelievable," Mr Taggart said by phone from his home in Bass River, near the lockdown area.

"People live here because of the peace and quiet and it's just an absolute tragedy."

Mr Taggart said he did not know Mr Wortman well, but spoke to him a few times when he telephoned about municipal issues.

Suspect divided time between hometown and Halifax business

He said Mr Wortman owned a few other properties in the community and was believed to divide his time between Portapique and his business in Dartmouth, a suburb in the provincial capital Halifax, about 140 kilometres to the south.

"You just don't even dream that this is going to happen," he said.

"I can't fathom it."

Police block the highway in Debert, Nova Scotia. ( AP: The Canadian Press/Andrew Vaughan )

Mass shootings are relatively rare in Canada, which has tighter gun control laws than the United States.

The worst incident in Canada in recent years happened in January 2017, when a man shot dead six people at an Islamic cultural centre in Quebec City.

In August 2018, a man in the province of New Brunswick, which borders Nova Scotia, shot dead four people, including two police officers, in an apartment complex.

In June 2014, in the same province, a man shot dead three police.

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