Young youths in the vicinity of wells , ages 13 to 18 were singled out for killing , witness says . ` ` They threw petrol bombs into houses and opened fire on anyone trying to flee , '' witness says .
Young victims in the village of Njaba , ages 13 to 19 were singled out for killing , witness says . `` They hurled petrol bombs into homes and opened fire on anyone trying to flee , '' witness says .