Altaf Hussain said that Nadeem Ahmad was a witness in C.I.D center bomb blast and identified the terrorists involved in the tragic bombing.
He claimed that Nadeem Ahmad was continuously receiving death threats from extremist elements.
MQM chief said that terrorists belonging to banned outfits killed three MQM MPAs, Sajid Qureshi, Syed Raza Haider and Manzar Imam in the past.
He was of the view that MQM is being punished for its strong stance against Talibanisation of the country.
Hussain appealed Army chief, Prime Minister Pakistan, Interior Minister and other high officials to take notice of the incident and bring the extremist elements involved in the killing to justice.
MQM worker Nadeem Ahmad was killed after being identified by terrorists while he was sitting at a shop in Orangi Town area.