NEW : At least 68 others are injured . The blast is the deadliest attack in Kabul since a suicide car bombing killed at least 80 people on April 7, 2009. In that attack , a Kenyan man pleaded guilty to being a member of the Islamic militant group Al-Shabaab and was charged with causing grievous bodily harm . Police suspect Al-Shabaab or sympathizers of Al-Shabaab . Grenade attacks have rocked Nairobi in recent months .
NEW : At least 68 others are injured . The blast is the deadliest attack in Kabul since a suicide car bombing killed at least 80 people on April 7, 2009. Police suspect Al-Shabaab or sympathizers of Al-Shabaab . Grenade attacks have rocked Nairobi in recent months .