The bespectacled gunman at the heart of the tragedy in the quiet New York town of Binghamton was identified as Jiverly Voong, 41, of Vietnamese descent, who until early March had been taking classes at the American Civic Association.

Police said early on Friday, that Voong, who had legally changed his name from Wong, donned body armour, blocked the centre's back doors with his car and then burst into the front of the building in a hail of gunfire.

Police chief Joseph Zikuski said, without uttering a word, Voong shot two receptionists, killing one, then strode into a classroom where an English lesson was being held and shot dead another 12 people, injuring three more, before turning the gun on himself.

The alarm was raised by the surviving receptionist, hailed as a hero by the police chief, who played dead after being shot in the stomach. She then crawled under her desk to call 911 on her mobile phone.

She and the other three injured were still being treated in hospital. Two were in a critical condition.

The small community, 215km north-west of New York city, voiced shock at the weekend at the violence.

American Civic Association president Angela Leach said, ''That this tragedy should have happened in our community to our friends who only wanted to advance their knowledge and love of America is unbearable.

''Whatever drove this individual to do what he did, I cannot possibly fathom,'' she added, vowing to continue the centre's work ''to help people realise the dreams of American citizenship''.

The names of the victims had not yet been issued.

Voong, who had a gun permit since the late 1990s, had recently lost his job at the Shop Vac assembly plant, which the New York Daily News reported had closed down in November.

A former co-worker of Voong quoted in The New York Times said he was surprised to see Voong at a local gym three times that week, including the night before the shootings.