What is Gujarat's 100-year-old Diwali tradition of 'Ingoriya war'?

'Ingoriya war' is a 100-year-old Diwali night tradition in Gujarat's Savarkundla, where rival groups throw burning, gunpowder-filled ingoriya (hingot) fruits at each other. Unlike a bomb, the fruit doesn't explode but emits a stream of sparks and flame as it travels. The fight traditionally occurs between villagers of Savar and Kundla, separated by the Navli River.