File this one under well, duh:

A hand grenade being used instead of a ball in a game of catch exploded early on Saturday killing three youths in this Bosnian town, police and news agencies said.

Two youths aged 19 and 20, one of them from neighboring Croatia, were killed instantly while a 20-year-old woman died on her way to hospital, police said. Her sister was slightly injured but two other youths suffered serious injuries.

I bet that shape puts a mean spin on it.