Medical examiners have identified the remains of a man who died at the World Trade Centre on 9/11 - 16 years after the terror attacks took place.

This is the first new identification made by scientists since March 2015, in what has become a painstaking and ongoing effort to offer closure to families.

At the request of his relatives, the man's name has not been publicly released.

Of the 2,753 people killed by hijackers who crashed planes into the twin towers on September 11th 2001, more than 1,100 are yet to have any remains identified.

The New York City medical examiner's office has begun to use new, more sensitive DNA technology in its attempt to connect more than 21,900 fragments to victims.

Few full bodies were recovered after the giant skyscrapers burned and collapsed - and the effects of heat, bacteria and chemicals have made it difficult to analyse remains.

Medical examiners have recently been using a process that involves pulverising the fragments to extract DNA, and comparing it to a collection of genetic material collected from victims and their relatives.

In some cases, scientists have re-examined the same bone fragment 10 or more times - hopeful that advancements in technology will provide answers.

In total, nearly 3,000 people were killed in the 9/11 terror attacks, which were claimed by al-Qaeda and its then leader Osama bin Laden.

A hijacked American Airlines flight crashed into the Pentagon in Arlington, Virginia, killing 187 people.

Another flight, United 93, was also taken over and believed to be heading for Washington DC, but it crashed into a field in Pennsylvania after the passengers and crew tried to regain control.