Country's top organisation to probe militant attacks, National Investigative Agency, is facing heat from a section of Opposition parties for not being able to prove charges against all accused of 2007 Mecca Masjid Blast case. The Congress has said that the NIA is fast losing its credibility in the country. Senior Congress leader Ghulam Nabi Azad said that acquittals are happening in each case since the government was formed four years ago and people are losing faith in the agencies. On the same lines, poet and lyricist Javed Akhtar has taken a sarcastic jibe at the agency. Taking to Twitter, Akhtar on Wednesday wrote that NIA can now probe inter-community marriages in the country. "Mission accomplished !! My congratulations to NIA for their grand success in Mecca Masjid case. Now they have all the time in the world to investigate inter-community marriages," Akhtar wrote on Twitter. The former Rajya Sabha Member of Parliament was referring to the Hadiya case, where the marriage of a Hindu woman with Muslim male is under NIA scanner for possible terror angle. Hyderabad MP and AIMIM chief Asaduddin Owaisi has also said that justice has not been delivered in the case. Owaisi said that majority of the witnesses turned hostile after June 2014, a time when BJP dispensation under Narendra Modi had taken over at the Centre. "What will be left of the criminal justice system if such biased prosecutions continue justice has not been done?" Owaisi had questioned. The five accused, which included Hindu leader Swami Aseemanand, were acquitted in the case on lack of evidence. Later, the judge who pronounced the verdict also resigned barely hours after the judgment citing personal reasons, a development which added to the controversy. Congress leader Kapil Sibal also slammed the NIA. Taking to Twitter, the Congress leader said: \u201cMecca Masjid bomb blast. 9 killed 58 injured. NIA must be honoured for proving there was no killer!\u201d. He further added: \u201cTask well done ! Desh badal chuka hai !\u201d. Former JD(U) leader Sharad Yadav also questioned the decision. The JDU leader expressed surprise that no one was found guilty in Mecca Masjid blast case. "More surprisingly is the Judge who gave verdict resigned soon after. If there was no one guilty found then who were involved. People are confused as to who will give justice to siblings & families of those who died (sic),\u201d Yadav said. On the other hand, BJP leaders have used the verdict to slam the Congress over charges of "Hindu terror". At a press conference addressed in the national capital following the NIA court verdict, BJP spokesperson Sambit Patra demanded an apology from Congress president Rahul Gandhi and his mother Sonia over their party's narrative of "saffron terror".