Uniindia: Amritsar, Aug 27 (UNI) With the arrest of seven persons, including a man who had planted an Improvised Explosive Device (IED) beneath the Sub-Inspector’s car in Amritsar, Punjab Police has unraveled yet another case of terrorist-gangster nexus working to disturb peace in the border state as it turned-out to be the handiwork of Canada-based gangster Lakhbir Singh alias Landa, said Director General of Police (DGP) Punjab Gaurav Yadav here on Saturday.