Perambalur, Three motorcycle-borne unidentified gang robbed Rs 3.30 lakh cash from Tamil Nadu State Marketing Corporation Limited (TASMAC) employees at knife-point in Padalur village in this district late on Monday night.Police sources said on Tuesday S.Manivannan (45), who was working as a supervisor of TASMAC retail outlet at Oothankaal village was riding a motorcycle along with the helper P.Suresh (40) with the collection amount, when they were intercepted by the gang.The robbers, who came on a motorcycle, brandished a knife and robbed the cash bag from the duo and escaped under the cover of darkness.Two of the robbers reportedly wore helmets, while another one wore a face mask.The Padalur police have registered a case and are searching for the gang.