NEW : MQM and the office of Pakistan 's Prime Minister cause violence in Pakistan . Muhammad Hussain , 60 , leads Pakistan 's Mutahida Qaumi Movement from the UK . He was arrested at his London home Tuesday in connection with a money smuggling probe . MQM , a force in Sindh province , has second - largest contingent in the provincial assembly .
NEW : MQM and the office of Pakistan 's Prime Minister condemn violence in Karachi . Altaf Hussain , 60 , leads Pakistan 's Mutahida Qaumi Movement from the UK . He was arrested at his London home Tuesday in connection with a money laundering probe . MQM , a force in Sindh province , has second-largest contingent in the provincial assembly .