Workers at the World Trade Center site in New York have discovered human remains in an abandoned manhole.

On Thursday a utility crew found bones large enough to be arm or leg bones. Medical authorities will try to identify the remains.

The twin towers of the World Trade Center collapsed on September 11th, 2001, following a terrorist attack. Nearly 3,000 people were killed. For more than a thousand of those victims, no remains were ever located or identified.

Some family members of the victims expressed disappointment that authorities were still locating remains more than five years after the buildings fell.

City officials said Friday they would conduct another search to recover any human remains that might still be on the site.

Some information for this report was provided by AP and AFP