KABUL, Afghanistan — A bomb on Friday killed two guards assigned to protect a provincial leader in southern Afghanistan.Amanullah Hotak, the head of the provincial council in Uruzgan province, said the remote-controlled bomb attached to a bicycle was detonated as his vehicle traveled past it. He said he escaped injury, but that two other body guards were injured in the blast.The incident occurred in Dihrawud district, a dangerous area in the south of the province.