Beyond analysis this requires impartial investigation that goes beyond surface level inspection.

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The mayor of Villers-le-Bel, Didier Vaillant, appealed for calm and said he would ensure there was "an impartial investigation, for full light to be shed" on the accident.

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For the government, Commons leader Sir George Young said he supported the decision to refer the matter for a "full and impartial" investigation as the "right course of action".

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He said his investigation would be impartial, and that he would focus on up to six people who he said were most to blame for the violence.

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