There never were any mass graves in Belgrade (excluding those full of Serbs and Jews dating back to WWII, and those filled by Tito's Communists after WWII).
Mass graves in Belgrade were a hoax orchestrated by the late Zoran Djindjic and his cronies and the West. The purpose was to score some points for the Hague Circus. It failed, obviously. Same goes for the freezer truck.
Yeah yeah, and you're just a figment of the collective imagination as well.