BRANTFORD, Ont. -- Prime Minister Stephen Harper is congratulating American authorities for their quick work tracking down suspects in the Boston Marathon bombings.

Harper says the "rapid action" of U.S. investigators in the manhunt is helping to bring a conclusion to Monday's "terrible events."

The bombings killed three people and wounded more than 180 others, raising the spectre of another terrorist attack on U.S. soil.

Harper says Canada stands ready to assist American officials if called upon.