I think we should wait for the claim to be proved in a court of law first, and then we can raise all the fingers in many directions. That said, it is now the duty of the government to probe the allegations both in national and international courts of justice. And like always if the government rests to mere rhetoric, then the thing is very obvious - for MQM of its involvement and for PML'N of its bigotry and dirty alliance.
And to add here such political crises is part of national security challenges that Pakistan faces today.