A criminal investigation for "war crimes" was opened in France against the Assad regime for the abuses committed in Syria between 2011 and 2013, AFP reported late Tuesday.Paris prosecutors opened a preliminary war crimes inquiry on September 15, a source close to the case and a diplomatic source said.The investigation is drawing in particular on evidence provided by a former Syrian army photographer known by the codename "Caesar", who defected and fled the country in 2013, bringing with him some 55,000 graphic photographs of scenes from the brutal conflict.