Assam Police picked up 52 persons from various places of Guwahati on Sunday in connection with the grenade blast at Paltan Bazar while 12 people were picked up in Dhubri in connection with stabbing cases that left one dead and two injured on Saturday.State Law and Order IGP L R Bishnoi said that a strict vigil is being maintained by army and security forces to maintain law and order. Indefinite curfew is continuing at Dhubri and Bilasipara sub-divisions since last evening as a precautionary measure. Additional companies, one each of Rapid Action Force and CRPF have been deployed.On the other hand, search operation is on to nab the culprits of Saturday’s grenade blast at Paltan Bazar area in Guwahati.One CRPF personnel died and 12 people, including three CRPF, were injured in the blast. The condition of all the injured persons is stable now.Meanwhile, North East Frontier Railway will run another special train on 20th of this month between Guwahati and Bangalore for those who had returned home in the wake of fake SMS threat.Assam government will provide free tickets to Chennai and Bangalore bound passengers.All persons who are willing to avail free tickets can register their names with the Deputy Commissioners on or before 13th of this month.North East Frontier Railway already ran two special trains to Bangalore.