US Chinook helicopter
Media playback is unsupported on your device
Video

US Chinook crash: Search of wreckage in Afghanistan begins

David Cameron says his thoughts are with the families of US military personnel killed when their helicopter crashed in Afghanistan.

The 31 troops included members of the elite Navy Seals unit. They died alongside seven Afghan commandos.

Marcus George reports.

Go to next video: Tributes paid to US Chinook crash sailor