UN-mandated rights investigators said Monday they were probing 14 alleged chemical weapons attacks in Syria, but said they were still unable to pin the blame on either side. \"We\'re investigating 14 cases of alleged chemical weapons use,\" said Paulo Sergio Pinheiro, head of an independent commission inquiry set up by the UN Human Rights Council. Pinheiro told reporters that giving the team\'s difficulties in gathering evidence -- it has not been admitted to Syria -- it was not possible immediately to establish responsiblity for the attacks, committed since it started its probe in September 2011.