PALAKKAD: The arrest of four PFI activists in connection with the killing of RSS member A Sreenivasan was recorded on Thursday evening. The four arrested are Bilal, Rizwan, Riyaz Khan and Sahad, all natives of Palakkad district. They were part of the conspiracy as well as members of the attack team but they did not take part in hacking Sreenivasan to death directly. The six persons who hacked Sreenivasan are still in hiding. The arrested four had accompanied the six-member gang to the crime location, said ADGP Vijay Sakhare.