Depending on the situation, I would either pray or I would yell to these men to stop in the name of Jesus because Jesus loves you! In fact, I cannot find the source right now, but I heard a report from some believers where they were held at gun point. However, when they started to sing about Jesus, these men with guns then left. Granted, each situation is different, but we are to love and not to attack under this current dispensation. Trust me, I did not always believe that way. But the Scriptures have a way of talking to our heart about the Truth. You either want to accept what God's Word says or you won't want to accept it. Jesus never advocated violence and neither did any of the other apostles. For there were many times believers were persecuted for their faith. It mentions absolutely ZERO about any physical battles that they might have had in those persecutions. For surely if you are being persecuted for your faith, would you then not fight back? For your thinking outwardly or from a carnal perspective that God is not going to do good in this situation or any situation unless YOU do something so as to save yourself or others. I have news for you, my friend. Jesus is the One who saves. Not you, me, or the other guy down the street. For did not Jesus say to Peter that he could have called down like a whole ton of angels to protect him? In other words, Jesus did not need Peter's sword.
But what if, what if something bad happens because you did not take action in trying to use a weapon to make things right?
Well, did you ever read the story of Joseph and what he said to his brothers later on when he was in Egypt?