波士顿爆炸现场上空禁航 休班警察被要求报道(图)

　　Boston （CNN） -- As the horror of the explosions near the finish line of the nation's most famous marathon sank in, government officials mobilized to respond on Monday afternoon.

　　FBI director Robert Mueller briefed President Barack Obama by telephone, the White House said.

　　Aviation authorities banned planes from flying over of the site of the explosion, the Federal Aviation Administrion said. The temporary flight restriction came at the request of law enforcement and extends three nautical miles in all directions, up to a height of 3,000 feet, FAA spokeswoman Arlene Salac said.

　　All off duty-police officers in Boston were told to report to their districts, CNN affiliate WHDH reported, and the Red Cross sent additional blood products to Boston-area hospitals, spokeswoman Anne Marie Borrego.

　　And law enforcement authorities from Atlanta to San Francisco said they were on heightened alert.

　　New York's Mayor Michael Bloomberg said the city had 1,000 officers assigned to counterterrorism duties, "and they -- along with the entire NYPD and the investments we have made in counterterrorism infrastructure -- are being fully mobilized to protect our city."

　　In Miami, police said they were increasing security at critical infrastructure sites, while the Los Angeles Police Department restated its advice to the public: "If you see something, say something."

　　Attorney General Eric Holder instructed the Justice Department to deploy its "full resources" to the investigation into the blasts that killed at least two people and left dozens injured.

　　He spoke to FBI director Mueller, and to the U.S. Attorney for the District of Massachusetts, Carmen Ortiz. Her office is coordinating responses from the Justice Department, the FBI, the Bureau of Alcohol, Tobacco and Firearms and other law enforcement officials.

　　Homeland Security Secretary Janet Napolitano was briefed, and she ordered her department to provide "whatever assistance is necessary" to state and local authorities, an administration official said.

　　London's Metropolitan Police said they were reviewing security arrangements for the London Marathon, which is due to take place on Sunday.

　　The race's chief executive, Nick Bitel, said organizers were "deeply saddened and shocked," and called it "a very sad day for athletics and for our friends and colleagues in marathon running."