1.2 mm emission map of NGC 6357 complex. Filled circles mark the Flat/class I objects, open triangles mark the class II objects. The filled asterisks show known massive stars in Pismis 24. The open diamonds show the YSO candidates selected from Fig. 6. The surface density of YSO candidates is denoted with contours. Three overdense regions are identified, corresponding to Pismis 24 and two newly found clusters.