They also concluded that the truck tyre bomb used in the yesterday's attack was of high intensity and suspected to be RDX but its exact composition would be confirmed only after the forensic report.

Police teams were sent to several places in UP, Haryana and Punjab after a thorough search at his house in Patiala drew a blank.

An explosives-packed tyre was hurled at the motorcade of Dera head Gurmeet Ram Rahim Singh at Butana in Haryana's Karnal district while he was returning after a court appearance in Ambala.

Eleven people, including 6 security men were injured when one of the vehicles burst into flames.

The name of Bakshish Singh, who is out on parole since 2003, cropped up during interrogation of the truck's driver Mahinder (35) of Assandh in Karnal and cleaner Swaran (20) of Mansa, Karnal Superintendent of Police A S Chawla said.

He told reporters the police probe indicated that Singh, a member of Bhindranwale Khalistan Tiger Force was living in Patiala after being released on parole from the high-security Nabha jail, was the ‘mastermind’ of the attack.