Boston Marathon blasts: Leaders react to explosions

U.S. President Barack Obama: 8220;We still do not know who did this or why. But make no mistake: we will get to the bottom of this. Any responsible individual,any responsible groups will feel the full weight of justice.8221; Massachusetts Governor Deval Patrick

8220;This is a horrific day in Boston. My thoughts and prayers are with those who have been injured.8221;Stephen Harper,Prime Minister of Canada: 8220;It is truly a sad day when an event as inspiring as the Boston Marathon is clouded by such senseless violence. Our thoughts and prayers are with those injured or affected by this horrible incident.

We stand with our American neighbors in this difficult time.8221;

Former Mexican President Felipe Calderón,currently a teaching fellow at Harvard and a spectator at the marathon: 8220;It8217;s unavoidable to remember that the planes that were hijacked and struck the twin towers on September 11th departed from Boston.8221;U.S. Senator Dianne Feinstein,Democrat from California who is chairman of the Senate Intelligence Committee: 8220;It8217;s diabolical 8230;

We have special efforts at the World Series and football games and baseball games and the Masters. And yet here8217;s some people that picked a 25-mike run,which is very hard to guard. I don8217;t believe we are complacent about our security.8221;U.S. Senator Saxby Chambliss,Republican from Georgia,who is vice chairman of the Senate Select Committee on Intelligence:

8220;As the evidence mounts that this was a terrorist attack,our intelligence and law enforcement agencies must do whatever is necessary to find and interrogate those responsible so we can prevent similar attacks.

U.S. Congressman Peter King,Republican from New York,who is chairman of the Homeland Security Subcommittee on Counterintelligence amp; Terrorism and a Member of Select Committee on Intelligence: 8220;Americans will not be deterred by terrorism. We will hunt down and bring to justice the cowards responsible for today8217;s attack.8221;

New York City Mayor Michael Bloomberg 8220;As law enforcement authorities investigate today8217;s explosions in Boston,I ask all New Yorkers to keep the victims and their families in your thoughts and prayers the NYPD has stepped up security at strategic locations and critical infrastructure.

We have 1,000 members of the NYPD assigned to counter terrorism duties,and they along with the entire NYPD and the investments we have made in counter terrorism infrastructure are being fully mobilized to protect our city.8221;