Complex sentence: The combined STF checked all the vehicles passing in the area and also kept vigil in the forests bordering the two states and came to know that Veerappan's gang was reduced to only five memebrs, one of them being a TNLA activist.
Split into simpler sentences: The combined STF checked all the vehicles passing in the area and kept vigil in the forests bordering the two states. They came to know that Veerappan's gang was reduced to only five members, one of them being a TNLA activist.