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.”

He says Canada is prepared to assist American officials if called upon.

Harper is also passing along condolences to the families of the three people killed and the more than 170 others injured in Monday’s blasts, and to the family of a police officer authorities said was fatally shot by one of the two bombing suspects last night.

Harper made the comments during a skills-training grant roundtable at an SC Johnson office in Brantford, Ont., west of Toronto.

Everyone in Boston is being told to stay home as authorities search for a suspect who fled after a shootout with authorities where explosives were thrown at police.

A suspect was fatally shot in the exchange.

Family members have identified the suspects as two brothers from the Russian region near Chechnya, which has been plagued by an Islamic insurgency.