KABUL : Seven schoolchildren were killed and three wounded by a roadside bomb in southeastern Afghanistan on Monday. The bomb was planted on the side of a main road in the Khairkot district of Paktika province, and exploded when the children stepped on it while playing. The children were aged 7-12 and were in elementary school. The injured children were taken to hospital.  No one has yet claimed responsibility for the incident, but roadside bombs are the Taliban’s weapon of choice in their 12-year war against US-led and Afghan security forces.