Maidan Shar (Afghanistan), April 30 : Three children were killed and two others injured as a mortar mine, left over from past wars, went off in Afghanistan's eastern Wardak province, said a statement of provincial government released here. A group of children was playing with the toy-like device in Sayedabad district on Friday when it suddenly exploded, killing three children on the spot and injuring two others, one in critical condition, the statement added on Saturday. A similar blast killed three children in Afghanistan's eastern Logar province last week, Xinhua news agency reported. Afghanistan reportedly is one of the most mine-contaminated countries in the world as dozens of people, mostly children, are killed and maimed every month due to blasts of unexploded devices left over from the past four decades of wars and civil conflicts. /IANS