American's worst ever gun tragedy leaves 28 dead

The suspect - named as 20-year-old Adam Lanza - turned his gun on himself following the killing spree at Sandy Hook Elementary School in Newtown, Conneticut.

Another victim, thought to be Lanza's mother Nancy, who was a teacher at the school, was discovered at an address in Newtown.

The gunman used two semi-automatic pistols, a Glock and Sig Sauer, as well as a rifle and reportedly wiped out an entire classroom of young children and shot several in a second class before taking his own life.

Witnesses said he went from room-to-room shooting people after first killing the principal Dawn Hochsprung and psychologist execution-style after they confronted him in the hallway.

Students described being ushered from their classrooms hand-in-hand, with their eyes closed, to the safety of a nearby fire station as police converged on the school.

A law enforcement official said the school shooting suspect died from a self-inflicted gunshot wound, and that his older brother Ryan was being held for questioning.

The shootings happened n one section of the school, in two rooms, according to Connecticut Police lieutenant Paul Vance.

Speaking to journalists, he said: "There were 18 children who were pronounced dead at the school.

"There were two that were transported to area hospitals and pronounced dead at area hospitals. And there were six adults pronounced dead at the scene, at the school.

"The shooter is deceased in the school."

US President Barack Obama wiped tears from his eyes as he addressed the American people, telling them: "Our hearts are broken today."

He said the nation had been 'through this too many times'.

In an emotional televised address from the White House, Mr Obama said: "I offer Governor Malloy my condolences on behalf of the nation, and made it clear he will have every single resource that he needs to investigate this heinous crime, care for the victims, counsel their families.

"We endured too many of these tragedies in the past few years. And each time I learn the news, I react not as a president, but as anybody else would, as a parent. And that was especially true today. I know there is not a parent in America who doesn't feel the same overwhelming grief that I do.

"The majority of those who died today were children. Beautiful little kids between the ages of five and 10 years old."

The President paused for some seconds and wiped away tears before continuing: "They had their entire lives ahead of them. Birthdays, graduations, weddings, kids of their own. Among the fallen were also teachers, men and women who devoted their lives to helping our children fulfil their dreams.

"So our hearts are broken today. For the parents, and grandparents, sisters and brothers of these little children, and for the families of the adults who were lost.

"Our hearts are broken for the parents of the survivors as well, for, as blessed as they are to have their children home tonight, they know that their children's innocence has been torn away from them too early, and there are no words that will ease their pain."

The attack was the latest of several mass shootings in the US this year, including the "Batman" cinema killings, and the death toll approached the 2007 Virginia Tech massacre, in which 32 were killed.

The Queen and the Prime Minister led the UK tributes to the victims.

In a message sent to President, the Queen said she was "deeply shocked and saddened" to hear of the shootings.

Mr Cameron took to Twitter to say he was "devastated" by the shootings and described the death of so many children as "truly heartbreaking".