The Blood Libel - the accusation that Jews kill Christian children, has a long history. This is a version recorded without challenge by Socrates Scholasticus.
The Jews commit Another Outrage upon the Christians and are punished.
Soon afterwards the Jews renewed their malevolent and impious practices against the Christians, and drew down upon themselves deserved punishment. At a place named Inmestar, situated between Chalcis and Antioch in Syria, the Jews were amusing themselves in their usual way with a variety of sports. In this way they indulged in many absurdities, and at length impelled by drunkenness they were guilty of scoffing at Christians and even Christ himself; and in derision of the cross and those who put their trust in the Crucified One, they seized a Christian boy, and having bound him to a cross, began to laugh and sneer at him. But in a little while becoming so transported with fury, they scourged the child until he died under their hands. This conduct occasioned a sharp conflict between them and the Christians; and as soon as the emperors were informed of the circumstance, they issued orders to the governor of the province to find out and punish the delinquents. And thus the Jewish inhabitants of this place paid the penalty for the wickedness they had committed in their impious sport.
Translation as in Nicene and Post-Nicene Fathers
Sources: Medieval Sourcebook