There are suicide attacks just about everyday in Afghanistan but one earlier this month was especially devastating. It killed four students from the Skateistan school in Kabul. Skateistan combines skateboarding with education for Kabul's street kids and the four youngsters were killed by a teenaged Taliban bomber. to help remember them Skateistan students will participate in an International Peace Day Festival in Kabul tomorrow. The BBC's Quentin Sommerville reports.