Ruling JD(U) leader Mithilesh Kumar Singh was today shot at and critically injured by unidentified gunmen at Afzalpur village in Bihar's Gaya district. <br/><br/>The gunmen fired at Singh, president of JD(U)' Sherghati block, critically wounding him. <br/><br/>Sources said, he was soon sent to A N Medical College and Hospital in Gaya where he is being operated upon.<br/>