New York has marked the end of the efforts to recover human remains from the debris of the World Trade Center with a ceremony attended by the relatives of those who died.

Many relatives brought photographs of their loved ones

Nearly two million tonnes of rubble were brought to the Fresh Kills rubbish landfill in Staten Island following the 11 September terrorist attacks, which destroyed the centre's twin towers.

In the months following, retrieval workers sifted through the debris searching for the remains and the personal belongings of some of the nearly 3,000 people who perished in the attack, as well as criminal evidence.

"We are here because of the worst of humanity," said New York Mayor Michael Bloomberg during the ceremony at the site, which opened with a sombre rendition of the national anthem and a sermon.

"At the same time, we see the best here - the people who worked here to recover the remains, who worked here to get some kind of closure."

Ten month search

A total of 54,000 items were retrieved from the site, referenced, and whenever possible, handed back to the families.

We are here because of the worst of humanity - at the same time, we see the best here

Michael Bloomberg New York mayor

At some stages of the operation some 7,000 tonnes of material were being processed a day.

Workers picked out every personal belonging they could find, from jewellery to tickets, and also became familiar with recognising human remains.

So far, forensic investigators have been able to identify 1,229 people, but they have warned relatives that as many as 800 of the victims may never be positively identified.

While they will continue their work, all search activities have now concluded at the Fresh Kills site.

The last truckload of debris arrived from the site of the twin towers in lower Manhattan at the end of last month, and the shovels, cranes and conveyer belts used for sorting have, for the most part, been cleared away.

In May, the site of the World Trade Center was also officially closed and last month, relatives of victims gathered for a final public farewell ceremony.