With the Boston Marathon one week away, some Manitoba runners who witnessed the deadly bombing at last year's event are determined to return, while others are having second thoughts.

Fifty-one Manitobans are registered to join the approximately 36,000 runners in this year's marathon on April 21.

Last year's Boston Marathon was rocked by two deadly bomb blasts near the finish line that killed three people and injured more than 260 others, including runners and spectators.

"I remember so many people that were … the spectators that were there," said Peter Pazerniuk of Winnipeg, who took part in last year's marathon and witnessed the aftermath of the bombing.

Peter Pazerniuk

Winnipegger Peter Pazerniuk, who took part in last year's Boston Marathon and witnessed the aftermath of the bombing, says he's not going back this year. (CBC)

Pazerniuk said given what happened, he is not going to the Boston Marathon this year.

"Now that there's been an incident that, you know, [that] has hurt so many people, my wife's concerned about going back there," he said.

"I think it'd be different if I was about, I don't know, 90 or 100 years old — I'd probably go 'Bring it on! You can't stop me from running this marathon.' But I still want to be there for my kids."

'I had to get back'

Winnipegger Kevin Donnelly also witnessed the chaos from last year's bombing but he is going back to Boston for next week's marathon.

"There was never any doubt in my mind — I had to get back," he said.

Kevin ​Donnelly

Kevin Donnelly also witnessed the chaos from last year's bombing, but he plans to run in the Boston Marathon this year. (CBC)

Donnelly has received a special invitation to participate in this year's event, after he submitted his story to the Boston Athletic Association about how he was deeply impacted by the bombing.

"I think it's going to be tremendously emotional for everybody," he said.

"We have to celebrate that we've been able to live through it … and be alive and whole after."

Pazerniuk said he will run in the Manitoba Marathon in June, but he hopes to go back to Boston someday.

Two brothers are suspected of carrying out the Boston Marathon bombing.

Tamerlan Tsarnaev, 26, died after a gunfight with police days after the April 15, 2013, bombing attack, while he and his younger brother Dzhokhar, now 20, were trying to flee the city.

The younger Tsarnaev was later arrested and is awaiting trial on charges that could result in the death penalty if he is convicted.

With files from Thomson Reuters