We were patrolling the mountains, I think somewhere around LZ Sandra. I'm not sure if we were supposed to be in this certain area. The squad I was in had point, the going was rough. We came across this trail, we were told to take it so we could make better time because we had to rendezvous with another company from our battalion. We always get in trouble on trails, and this time was no different. We hadn't gone very far when we heard some movement above us. All of a sudden an M-79 round went off ahead of us. I heard the familiar thump of another round being fired so we knew it was coming from American G.I.'s . We started yelling to cease fire. Well, sure enough it was the company that we were supposed to meet. I don't know what happened but we were supposed to be a click apart. We had one man slightly wounded and the short timers were extremely shook up over the incident.