Ten young girls have been killed and two others were injured in a landmine explosion in eastern Afghanistan. The local governor says the girls, aged between nine and 11, were killed when one of them hit the mine with an axe as they were out collecting firewood, the BBC reports. Afghanistan is one of the world's most heavily mined countries and dozens of Afghans are killed by mines every year, some of which date as far back as the Soviet occupation. (More Afghanistan stories.)