Banned group Sikh for Justice (SFJ) claimed responsibility for the Rocket Propelled Grenade (RPG) attack at Punjab Police's Intelligence wing in Mohali in Sahibzada Ajit Singh Nagar District of Punjab on May 9, reports The Times of India on May 11. In a suspected audio message to Himachal Pradesh Chief Minister (CM), Jai Ram Thakur, SFJ's Gurpatwant Singh Pannun issued a warning. The voice message transcripts, "Lesson for Himachal chief minister - learn from grenade attack at Mohali police headquarters - attack could have been at Shimla headquarters. CM Thakur SFJ advise - we raised flag at Dharamshala HQ, do not provoke the Sikh community. SFJ is going to announce Khalistan referendum 20-20 on June 6 in Himachal on day of voting. Do not provoke Sikh community and start violence because violence begets violence, CM Thakur. Message is from Gurpatwant Singh Pannu SFJ General Counsel." The Punjab Police are verifying the authenticity of the voice message. A probe is already ongoing and 20 suspects have been arrested in the RPG attack at Punjab Police's Intelligence wing case. Police are also planning to issue a red corner notice for Pannun.