GURGAON, April 6: A gang of armed assailants, believed to be of tribal ORIGIN, has struck again at two farmhouses at Chandu Buthera on the Sultanpur road, killing a chowkidar and injuring four others.In a late night assault, six armed men stormed into the Dutta farm. They tied up the watchmen Ramu and Bindeshwar, beat them up and later decamped with some cash.The police said the assailants were only wearing under-garments and had a yellow cloth wrapped around their faces.A case was then registered - based on the eyewitness account given by Shinde, Bindeshwar's brother. Deputy Inspector General, Gurgaon range, P.V. Rathee says: ``The manner in which the assault was carried out points to the involvement of the Pardi tribals.''However, the DIG was hopeful about arresting the gang. ``They have made a number of attempts on the farmhouses, which implies that their area of concentration remains confined to the farmhouses,'' said Rathee.The police are also exploring other possibilities.``The mostdisheartening factor is the non-cooperation of farmhouse owners. Despite our repeated pleas to keep armed guards at the farmhouses, they have remained indifferent,'' said Senior Superintendent of Police, Khushi Ram Dahiya.