Seattle Police K9 officer Craig Williamson stands with his explosives detection dog, "Dennis" as he patrols downtown Seattle, Monday, April 15, 2013, in reaction to explosions at the Boston Marathon finish line earlier in the day. A Seattle Police blog posting said that although there was no indication of a direct threat to Seattle, officers would be increasing patrols and activity around the city. (AP Photo/Ted S. Warren)
World responds to Boston bombing
In the wake of the Boston attacks, several countries, including France and Great Britain, have ordered local authorities to step up security and reinforce measures already in place.