This happened in 1956 during the Mau Mau uprisings in East Africa. The story is told by veteran missionary Morris Plotts.
A band of roving Mau Maus came to the village of Lauri, surrounded it, and killed every inhabitant, including women and children—three hundred people in all. Not more than three miles away was the Rift Valley Academy, a private boarding school where children were being educated while their missionary parents worked elsewhere. Immediately upon leaving the carnage at Lauri the Mau Maus came with spears, clubs, torches, and bows and arrows to the school, bent on destruction. You can imagine the fear of those children at the school. Word had already reached them about the destruction of Lauri. There was no place to flee. The only resource was prayer.
Out in the night, lighted torches were seen coming toward the school. Soon there was a complete ring of these terrorists about the school, cutting off all avenues of escape. Shouting and curses could be heard coming from the Mau Maus. Then they began to advance on the school, tightening the circle, shouting louder, coming closer. Suddenly, when they were close enough to throw a spear, they stopped. They began to retreat, and soon they were running into the jungle. A call had gone out to the authorities, and an army had been sent in the direction of the school to rescue the inhabitants.
But by the time the army arrived, the would-be assassins had dispersed. The army spread out in search of them and captured the entire band of raiding Mau Maus. Later, before the judge at their trial, the Mau Mau leader was called to the witness stand. The judge asked him, “On this night did you kill the inhabitants of Lauri?” The leader replied, “Yes.” “Was it your intent to do the same at the Rift Valley Academy?” “Yes.” “Well then,” asked the judge, “why did you not complete the mission? Why didn’t you attack the school?”
The leader, who had never read the Bible and never heard the gospel, replied, “We were on our way to attack and destroy all the people at the school. But as we came closer, all of a sudden between us and the school there were many huge men, dressed in white with flaming swords. We became afraid and we ran to hide!”