International inspectors reportedly discovered traces of chemicals used to make weapons at a Syrian military research site that had not been declared.
Reuters, citing unnamed diplomatic sources, reports that the Organization for the Prohibition of Chemical Weapons took samples in December and January from a Syrian military research site that tested positive for chemical precursors used to make sarin and VX nerve agents.
The Syrian government last year handed over 1,300 metric tons of chemical weapons after it pledged to eliminate its stockpile.
"This is a pretty strong indication they have been lying about what they did with sarin," one diplomatic source said. "They have so far been unable to give a satisfactory explanation about this finding."
The Hague-based OPCW did not immediately respond to TIME's request for comment.
Read more at Reuters