Blood libel is an old and prominent theme in anti-semitism, and still in use today.
Blood libels typically allege that Jews require human blood for the baking of matzos for Passover, although this element was absent in the earliest cases that claimed (the contemporary) Jews reenacted the crucifixion. The accusations often assert that the blood of Christian children is especially coveted, and, historically, blood libel claims have been made to account for otherwise unexplained deaths of children. (source)
Here are some historical and contemporary images invoking blood libel explicitly or implicitly:
More images here.