Update 3: 27 killed in US school shooting
Twenty-seven people have died, including 18 children, after a shooting at an elementary school in Connecticut, officials said.
Another official said the gunman is among the dead.
The killings happened at Sandy Hook Elementary School in Newtown, about 60 miles north-east of New York City.
Photos from the scene showed young students - some crying, others looking visibly frightened - - being escorted by adults through a car park in a line, with hands on each other's shoulders.
Barack Obama has been briefed about the shooting by his counter-terrorism adviser John Brennan, the President's Press Secretary Jay Carney said.
Mr Carney, who would not confirm any details, said the president would continue to receive regular updates throughout the day.