A memorial field of flags to commemorate victims of the September 11, 2001 terror attacks on the World Trade Centre has opened in New York's Inwood Hill Park, upper Manhattan.

The memorial contains three thousand American flags, each representing a victim of the attacks.

The Flag of Honour lists the names of those who died in the attacks, while the Flag of Heroes contains the names and ranks of the emergency and rescue workers who raced to the scene, and in many cases, right into the twin towers.

Visitors to the park are encouraged to walk among the flags and read the names of those who lost their lives in the attacks.

One local resident, Michael Oreilloi, said he felt quite moved to walk through the park knowing that each flag represented a life lost in the attack.

"And its very powerful to stand in the middle of this and feel the enormity of it. It's one thing to hear about numbers and things, but when you actually stand here and physically have a representation of people and their lives, it's just very powerful."

Flags from 92 nations were also raised at the memorial, representing the many countries that lost citizens that day.

An 18-foot-tall sculpture, a tribute to the World Trade Centre, as well as the 3000 flags will be on display through the weekend, ahead of the fifth anniversary of the attacks, along with displays from New York City's Fire and Police departments, and emergency service workers.