Ahmedabad: The CBI on Saturday opposed a plea by four Gujarat policemen seeking their discharge in the 2004 case of alleged fake encounter of Ishrat Jahan and three others on grounds of absence of state's sanction to prosecute them. Gujarat's Inspector General of Police G L Singhal, retired Deputy Superintends of Police Tarun Barot and J G Parmar, and SRP commando Anaju Chaudhary have also sought their discharge on grounds of parity of their cases with those of discharged police officers D G Vanzara and N K Amin in the same case. In their discharge pleas to the court of Special Judge P K Dave, the four policemen have also asserted that the government has not granted sanction to the CBI to prosecute them (under section 197 of the CrPC).