Twenty-seven people, including 18 children, have been killed in a shooting at a US school, one of the worst gun massacres in the country's history.
A law enforcement official said the suspect in the attack at Sandy Hook Elementary School in Newtown, Connecticut, is a 20-year-old man with links to the school.
Another official said the gunman was killed and apparently had two guns, one of which was a .223-calibre rifle.
Police in New Jersey were last night reported to be searching a location in that state in connection with the shooting.
The White House said President Barack Obama had been notified about the tragedy.
It was the latest of several mass shootings in the US this year, and approached the deadly scope of the Virginia Tech university massacre in 2007 in which 32 people were killed.
In yesterday's attack, most of the victims were children.
Photos from the scene showed pupils – some crying, others looking frightened – being escorted by adults through a car park in a line, hands on each other's shoulders.
The superintendent's office in Newtown, about 60 miles (96km) north-east of New York City, said the district had locked down schools, and schools in neighbouring towns also were locked down as a precaution.
Stephen Delgiadice said his eight-year-old daughter heard two big bangs, and teachers told her to get in a corner. His daughter escaped unscathed.
''It's alarming, especially in Newtown, Connecticut, which we always thought was the safest place in America,'' he said.
Mergim Bajraliu, 17, heard the gunshots echo from his home and raced to check on his nine-year-old sister at the school.
He said his sister, who was fine, heard a scream come over the intercom at one point.
He said teachers were shaking and crying as they came out of the building.
''Everyone was just traumatised,'' he said.
At the White House, spokesman Jay Carney said the administration would "do everything we can to support state and local law enforcement"'.
He would not say whether the shooting would make gun control a higher priority on the President's agenda, but he said there would be a day for discussion on that policy issue.
''But I don't think today is that day," he said.
