From July 5, 2009
The video shows 3 rioters armed with machetes charging at the police and ignoring the warning shots fired in the air. The police had no choice but to fire at them.
Two were killed, one was critically injured and more than 20 machetes were found in a bag they left.
(No way to confirm actual events)
Related... 140 Dead After Weekend Violence In China
Update: Here seems to be a longer version of the video.
36 large photos of the clashes in Urumqi.