The demand was made at a massive protest organized by the MQM in front of Karachi Press Club.
Addressing the gathering, MQM leader Qamar Mansoor said his party has adopted a legal course against Lal Masjid cleric Maulana Abdul Aziz for threatening Altaf Hussain.
He said that Maulana Abdul Aziz be arrested after registration of a case against him.
The MQM leader also demanded strong action against religious and political parties, which were supporting Taliban.
Senior MQM leader Hyder Abbas Rizvi condemned Maulana Abdul Aziz for releasing a threatening video statement against Altaf Hussain. “Maulana Abdul Aziz has hurt the sentiments of millions of people,” he said.
Later, MQM adopted a resolution, seeking registration of a treason case against Maulana Abdul Aziz.