Three brothers were killed and their 12-year-old sister was critically injured when a hand grenade they were playing with exploded in Jhal Magsi, an official said on Thursday. The three brothers — a five-year-old and twins aged eight — died instantly in the blast late on Wednesday in Jhal Magsi, a small town 375 kilometres southeast of Quetta, said Aslam Raisani, a government administrator. Their 12-year-old sister was critically injured and remained in hospital, he added.The children had found the grenade in a field used for farming and believed it was a toy. They were playing with the explosive device back at their home when it blew up, Raisani said. Scattered hand grenades and other unexploded ordinance are a legacy of ongoing feudal disputes in Balochistan.