Following the terrorist attack in Punjab's border district of Gurdaspur yesterday, senior police officers are trying to link all the leads to know how and from where the highly armed assailants entered the state. A DIG rank police officer from J&K and some army officers along with senior officers of Punjab police are discussing all the aspects threadbare. <br/><br/>Forensic teams have also reached Dinangar police station where the three terrorists barged in on early Monday morning. AIR correspondent reports that the teams are taking stock of the area where the terrorists were holed up and later killed by police in the evening and the arms and ammunition and other equipments including GPS system they were carrying. Team members have also checked the hijacked car in which terrorists reached the police station after killing a dhaba owner and firing on a bus.<br/><br/>Although some media reports are suggesting that as per the GPS details of terrorists, they had come from the neighbouring country but the senior police officers are still tight-lipped. <br/> <br/>Security has been beefed up all along the border with Pakistan and police has also stepped up vigil in the state by putting up nakas. Security all along the railway tracks and railway stations across the state has also increased. Divisional Railway Manager, Ferozepur Division told AIR that the technical and other staff members have also been directed to be vigilant.