Except as otherwise provided by general law, a judge of a district court may, within the scope of his general jurisdiction, issue warrants, summons, and subpoenas, including subpoenas duces tecum or other process, in civil, traffic and criminal cases, to be returned before his court, and may also issue fugitive warrants and conduct proceedings thereon in accordance with the provisions of §§ 19.2-99 through 19.2-104.