"Despite damning evidence, the accused including a former RSS member have been acquitted. God forbid, had they been Kashmiris / Muslims, they would be pronounced guilty & imprisoned without even a fair trial. Why such double standards and leniency towards saffron terror?" the former Jammu and Kashmir chief minister asked.
Mufti's reaction came hours after a National Investigation Agency (NIA) court acquitted all four accused, including Swami Aseemanand, in the February 2007 Samjhauta Express train blast which killed 68 people, mostly Pakistanis.
The NIA court had in January 2014 framed charges against Aseemanand and three others -- Kamal Chauhan, Rajinder Chaudhary and Lokesh Sharma. All of them were present in the court on Wednesday.
They had been charged with criminal conspiracy, murder, attempt to murder, sedition and more.
The blast on February 18, 2007 in the train, which runs between Delhi and Lahore, at Haryana's Panipat left 43 Pakistanis, 10 Indians and 15 unidentified people dead. A dozen people, including 10 Pakistanis, were also injured.
Aseemanand, a member of the right-wing group 'Abhinav Bharat', was arrested by the Central Bureau of Investigation (CBI) on November 19, 2010 from Haridwar, Uttarakhand, for alleged role in the 2007 Mecca Masjid blast in Hyderabad that killed 14 people.
The NIA, which questioned Aseemanand about his role in the Samjhauta blast case, said it had evidence against him and others.
Over 250 witnesses were examined during the trial, out of which some had turned hostile.
The charge sheet in the case was filed in 2011, four years after the incident.