Memorial service at Ground Zero
Media playback is unsupported on your device
Video

Key moments from 9/11 anniversary

The US has marked nine years since 9/11 amid controversy over plans for an Islamic centre near Ground Zero and a threat to burn the Koran.

Services were held at each location where the planes crashed and the names of those who died were read aloud at Ground Zero.

President Barack Obama urged respect for other religious faiths and paid tribute to those who lost their lives, during a speech at a service at the Pentagon.

There were also one-minute silences to mark the moment when the World Trade Center towers were hit and the time at which each tower fell.

Go to next video: NY mayor attends 9/11 service