More than 40 Manitobans participated in the Boston Marathon that was rocked by explosions on Monday.

At a Tuesday morning press conference, FBI officials said three people were killed in the blasts and more than 150 injured.

They also said a search of the area did not produce any undetonated bombs.

Kevin Donnelly from True North Sports & Entertainment Ltd in Winnipeg was one of the race participants. He believes all the Manitobans were safe.

He said he heard the explosions only five minutes after crossing the finish line.

“There were two explosions, one after another, maybe about 15 seconds apart - big huge plume of grey and black smoke,” he said. “Everybody is in shock. Everyone is in utter dismay.”

Shirley Lumb, executive director of the Manitoba Marathon, said officials here will look at potential changes.

“All we can do is plan and hope that we've crossed any Ts and in the end our plan will work and that we'll be able to manage anything that comes our way,” said Lumb.

Donnelly told CTV on Monday afternoon that all but one of the 41 runners from Manitoba had been accounted for. He said he believed the last runner was still on the course and not near the finish line at the time of the explosion.

Gerald Boulet and Marcel Sorin from Lorette had finished the race a half hour before the explosion.

It was Boulet’s second time running the marathon in Boston, but he said he likely won’t return for a third one.

"There's more important things than running marathons. There's family, friends. It puts your priorities in perspective,” he said.

More than 2,000 Canadians were taking part in the 42-kilometre race.

Prime Minister Stephen Harper issued a statement Monday afternoon.

"It is truly a sad day when an event as inspiring as the Boston Marathon is clouded by such senseless violence," he said. "We stand with our American neighbours in this difficult time."

The Department of Foreign Affairs has set up an emergency line -- 1-800-387-3124 -- to offer assistance to Canadians.

Multiple organizations are involved in the investigation into the explosions.

- with a report from Karen Rocznik and files from The Canadian Press