Cause of accident

I refer to the article regarding the road accident involving AFM soldiers and a jeep-load of illegal immigrants on their way to Safi barracks.

I find it mysterious why the police did not want to give any details as to what really caused the incident. Moreover, in another English language daily newspaper, one of the soldiers was quoted as saying: "We did the best we could. Now it is up to the police to find out what happened".

Was this accident the result of driver's error or is there something more sinister between the lines which the authorities do not want us to know?