The head of a UN investigative body for Syria, who is working to gather evidence about atrocities committed in the country, says in Damascus on Sunday that he had asked the new government for permission to begin fieldwork. After investigations conducted so far from a distance, "we documented hundreds of detention centres (...) Every security centre, every military base, every prison had their own either detention or mass graves attached to it", says Robert Petit, who heads the International, Impartial and Independent Mechanism (IIIM), created in December 2016 by the UN General Assembly. IMAGES AND SOUNDBITES