The 50-year-old member of the Sindh Assembly and his bodyguard, identified as Asif, were gunned down by drive-by assailants near a mosque.
Three shooters killed the provisional assembly member when he went to to Masjid-e-Aqsa located at Nazimabad to attend a funeral. He was reportedly performing ablutions when the gunmen opened fire.
While some of the reports published earlier state that the leader's bodyguard was seriously injured in the shooting, the latest reports state that he succumbed to his injuries at a hospital.
The authorities have identified the latest assassination as part of the a slew of targeted killings that has rocked Karachi in the recent past.
Following the murder of the member of MQM, a partner in the Sindh provincial ruling coalition led by the Pakistan Peoples Party (PPP), violence broke out in the financial hub of Pakistan, in which as many as 14 people were killed and 50 were injured.
Muttahida Qaumi Movement, which stands for United National Movement, is fourth largest political party and the largest liberal political party of Pakistan. It enjoys a stronghold in the province of Sindh.