Rouketopolemos (Greek Рουκετοπόλεμος, literally Rocket-War) is the name of a local traditional event held annually at Easter in the town of Vrontados (Βροντάδος) on the Greek island of Chios. As a variation of the Greek habit of throwing fireworks during the celebration of the service at midnight before Easter Sunday, two rival church congregations in the town perform an Rocket War by firing thousands of rockets across the town, with the objective of hitting the bell tower of the church of the other side.
The origin of this event is unclear, but local tradition holds that it goes back to the Ottoman era. According to local lore it was earlier performed with real cannons, until Ottoman authorities prohibited their use in 1889.
Reposted from 2008 to add this newer video: