A New Jersey State Police helicopter flies over Jersey City, N.J., Monday, April 15, 2013. New Jersey is securing its city, which sits along the Hudson River across from New York City, in the wake of explosions near the finish line at the Boston Marathon. (AP Photo/Julio Cortez)
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.