A commuter reads a newspaper featuring the Boston marathon bomb blasts on the front page, while waiting for a train at East Croydon station in south London, Tuesday, April 16, 2013. British police are reviewing security plans for Sunday's London Marathon, the next major international marathon, because of the bombs that killed three people at the marathon in Boston Monday. (AP Photo/Sang Tan)
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.