At least 10 people were killed or injured in the Afghan capital Kabul Sunday by a powerful bomb blast in front of a building used by U.S. soldiers, said an Interior Ministry source at the scene. According to statement from Afghan president, the explosion occurred in front of the Kabul office of an international security company, and killed at least seven people. Two Americans, three Nepalese and two Afghan nationals including a child have been confirmed dead, the statement said. Representatives of the ousted Taliban regime claimed responsibility for the attack. Taliban spokesperson Mufti Abdul Latif Hakimi said the blast had been detonated by a suicide bomber driving a goods van. In a statement, Afghan president Hamid Karzai said he was deeply disturbed by the explosion and has advised the government security organizations to undertake an immediate investigation into the explosion. "The president understands that as the people of Afghanistan move towards elections, the enemies of Afghanistan will expedite their efforts to harm the election process and threaten the people's security and prosperity," the statement said. --More 2328 Local Time 2028 GMT